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When using the gain substitution method with a pyramidal standard gain horn (SGH), it is common practice to use the on-axis NRL gain curves derived by Schelkunoff and Slayton [1]. Due to approximations in this formulation, Slayton assessed an uncertainty of ±0.3 dB for typical SGHs operating above 2.6 GHz. Since this uncertainty term is often one of the largest terms in the range measurement uncertainty budget for AUT gain, it is highly desirable to reduce it. Many studies in the past have attempted to improve upon Slayton’s expressions for SGH gain, but none have achieved widespread use. With the advent of high-performance computing (HPC), antenna simulations with computational electromagnetic (CEM) full-wave solvers are now capable of solving complex, electrically large models with high accuracy. This paper investigates the use of several commercially available solvers, including HFSS, CST, and FEKO to model the on-axis directivity and gain of a commercial off-the-shelf (COTS) X-band SGH. Relevant modeling techniques are described in detail and are shown to employ best practices as well as conformance with the IEEE 1597.1 and 1597.2 “Standards for Validation of CEM Modeling and Simulations” and “Recommended Practice for Validation of CEM Computer Modeling and Simulations,” respectively. The challenges and trade-offs of each CEM solving technique used, as well as their limitations, are discussed. Simulation errors are quantified via the IEEE standards, and other practical limitations of SGH manufacturability and measurement are discussed. Finally, the results from the CEM simulations are compared with the NRL gain curve and measured on-axis directivity and gain of the COTS SGH. Based on the compiled results of multiple simulations and measurements, this simulation methodology could be applied to other models of COTS SGH antennas to provide more accurate on-axis gain predictions. [1] W. T. Slayton, “Design and calibration of microwave antenna gain standards,” US Naval Res. Lab., Washington, DC, Rep. 4433, Nov. 1954.
The novel extension of the synthetic aperture radar (SAR) technique to the terahertz (THz) spectrum has emerging short-range applications, especially in an indoor environment. One of the key applications is the generation of a high-resolution indoor environment map in emergency scenarios such as a burning or smoky building, where optical technology might not provide any relevant information. The THz SAR map enables precise localization, classification, and material characterization of concerning objects which can assist in identifying the danger from electrical cables located in the walls and ceilings, and the structural integrity and failure of the walls/ceilings. Hence, the investigation of through-wall sensing at the THz spectrum is of vital importance. This paper addresses the through-wall sensing at the THz spectrum by employing the SAR technique. A miniature version of the wall using gypsum plasterboards is constructed, where the plasterboards are mounted on a frame. Two types of frames are considered, where one frame is of wood and the other is of metal. Additionally, electrical cables are placed between the plasterboards. This miniature version is quite similar to a practical environment. Besides, some of the considered components of the wall are in a burned state. For through-wall sensing, a vector network analyzer (VNA) based testbed is implemented and measurements are recorded in both transmission and reflection modes for three frequency spectrums, which are 75-100 GHz, 220-330 GHz, and 325-500 GHz. At the THz spectrum, the penetration capabilities are always of concern. Therefore, foremost, penetration losses among different components of the wall are investigated with transmission measurements. Further, to evaluate the sensing capabilities behind the wall, transmission measurements are recorded by considering the whole structure of the wall. Besides, relative attenuation among different frequency spectrums is presented. The addressed evaluation is also of significant interest in the area of wireless communication such as 6G and security. Lastly, in reflection mode, a 2D SAR trajectory is implemented and a 3D image of the wall is reconstructed. It is analyzed for identification and precise localization of the cables and frame-blocks. The identified components are further processed for burned state detection.
Among the near-field - far-field (NF-FF) transformations, that with spherical scan is the most appealing due to its feature to allow the whole radiation pattern reconstruction of the antenna under test (AUT). To considerably save measurement time, spherical NF-FF transformations for AUTs with one or two predominant dimensions, requiring a minimum number of NF data, have been developed by using the non-redundant sampling representations of the electromagnetic fields and adopting suitable AUT modellings. Another effective possibility to save the measurement time is to make faster the scan by collecting the NF data through continuous and synchronized movements of the probe and AUT. To this end, non-redundant NF-FF transformations with spherical spiral scan have been recently proposed by exploiting the unified theory of spiral scannings for volumetric and non-volumetric AUTs. However, the characterization of heavy and large AUTs (such as, e.g., a vehicle) in a NF spherical facility from measurements collected over the full scanning sphere can become infeasible. To ensure a mechanically stable support and guarantee a high repeatability of the measurements, a more viable way is to place the AUT on a turning metallic ground plane and characterize the considered AUT from the NF data acquired over a hemisphere. In recent works, instead to set to zero the NF data required by the classical NF-FF transformation, which would be acquired over the lower hemisphere, it has been proposed to synthesize them by properly applying the image theory, thus avoiding that the truncation error affects the FF reconstructions. This work aims to propose an efficient spherical spiral NF-FF transformation for volumetric AUTs, using a minimum number of spiral data, which, due to the presence of an infinite perfectly conducting ground plane, are collected over a proper spiral wrapping the upper hemisphere. Once the voltage NF data which would be acquired over the spiral wrapping the lower hemisphere will be properly synthesized, then an efficient 2-D optimal sampling interpolation scheme will allow the recovering of the NF data required by the classical spherical NF-FF transformation. Numerical tests will show the accuracy of the developed non-redundant spherical spiral NF-FF transformation.
A free-space material measurement using the scattering parameters of a planar MUT (material under test) placed between Tx and Rx antennas is suitable for non-destructively testing the MUT without physical contact and precise machining in a high-frequency range. Improving the measurement uncertainty of the material parameter of an MUT extracted from a free-space material measurement requires accurate and precise measurement of the scattering parameters of the MUT, which is highly dependent on the characteristics of impedance standard (or reflect standard) and method used in calibrating the material measurement system, including a VNA (vector network analyzer). A free-space material measurement system usually needs at least three independent reflect standards (e.g., short, open, and load for coaxial case) for the calibration at both sides of an MUT in free space. Unfortunately, it is not easy to implement the reflect standards in free space. Recently, a planar offset short has been proposed as a free-space calculable reflect standard. The magnitude of its reflection coefficient is unity, and the phase is the linear function of the offset of the short and the signal frequency. This paper reviews the recently developed one-/two-port calibration methods using a planar offset short for a free-space material measurement in a millimeter-wave frequency range. An adapter characterization scheme, which is widely utilized to measure the scattering parameters of a non-insertable device (e.g., SMA to 3.5 mm adapter) by using a two-tier one-port calibration, may be applied to a free-space one-port calibration. On the other hand, an unknown thru calibration method, widely used to measure the scattering parameters of non-insertable devices whose connectors could not mate together (e.g., a coaxial to waveguide adapter), may be applied to calibrate a free-space two-port measurement system. These works use three planar offset shorts as free-space reflect standard, which gives the phase difference of 120° between the reflection coefficients of the planar shorts at the center frequency of the operating frequency band of a waveguide. A review of the two calibration methods and measurement results in the W-band (75-110 GHz) will be presented.
Electromagnetic materials characterization at UHF and VHF frequencies is typically done with laboratory fixtures such as the coaxial airline or rectangular waveguide. These conventional methods require material specimens to be cut or machined to precision tolerances for insertion within the transmission line fixture. Measurement accuracy dictates there should be little or no air gaps between the specimen and the transmission line walls. Transmission line methods also require significant handling and multi-step calibration procedures to characterize a material specimen. This paper describes a new handheld measurement device that overcomes these limitations with a simple calibration and non-destructive measurement procedures. This new method applies an open-ended stripline sensor tuned to maximize measurement sensitivity in the 100 to 1000 MHz range. The sensor footprint is approximately 100 mm square and utilizes an integrated one-port vector network analyzer. It operates by measuring the amplitude and phase of the reflection coefficient when placed adjacent to a material specimen. While traditional transmission line methods employ analytical expressions to relate scattering parameters to intrinsic properties, The open-ended stripline sensor geometry and its interaction with the material cannot be easily modeled with an analytical approximation. Instead, it is modeled with a full-wave Finite Difference Time Domain (FDTD) code to develop the relationship between measured reflection and complex permittivity. This inversion method precomputes a translation table by iteratively modeling the measurement fixture across a range of complex permittivities and specimen thicknesses. From this inversion database, interpolation is then used to calculate the frequency dependent complex permittivity or sheet impedance of a given specimen. This paper provides details about the calibration and use of this new device as well as the material property inversion algorithm. Measurement examples of low-loss and lossy materials as well as resistive sheets are also presented and compared to more conventional transmission line results, and are discussed in relationship to measurement uncertainties.
Using a Higher-Order Basis Function based Method of Moments Analysis for Designing Compact Antenna Test Ranges Abstract:- Full wave electromagnetic simulation of a Compact Antenna Test Range (CATR) is not trivial given its electrical size. Typically, the reflector geometry is simulated using asymptotic methods using an assumed feed pattern, while RF absorber and its effects are ignored. A boundary element method of moments (MoM) implementation, using higher-order basis functions is a good numerical technique for analyzing these ranges since the equations are only solved at the interfaces between different homogeneous regions. There is therefore no need to discretize and solve equations for the fields in the large empty volume portion of the CATR, unlike when using Finite-Difference Time-Domain (FDTD) or Finite Element Methods (FEM). Using higher-order basis functions allows for the mesh size of the discretized CATR geometry to be as large as two wavelengths, reducing the number of unknowns while enabling fast, efficient solutions. In this paper, a commercial software package that uses MoM with Higher-Order Basis Functions is used to model a CATR that incorporates a blended rolled edge reflector. The results for the reflector and feed model are compared with asymptotic analysis results to show agreement. A realistic feed horn, support structure and RF absorber is then introduced to the model and its performance is also included to predict field distribution in the CATR test zone. Using this field solution the Poynting vector is calculated to visualize the flow of energy in the range and from these results proper RF absorber layout can be designed to ensure optimum test zone performance. It is also shown how feed structure absorber treatment impacts CATR test zone performance.
Using a Higher-Order Basis Function based Method of Moments Analysis for Designing Compact Antenna Test Ranges Abstract:- Full wave electromagnetic simulation of a Compact Antenna Test Range (CATR) is not trivial given its electrical size. Typically, the reflector geometry is simulated using asymptotic methods using an assumed feed pattern, while RF absorber and its effects are ignored. A boundary element method of moments (MoM) implementation, using higher-order basis functions is a good numerical technique for analyzing these ranges since the equations are only solved at the interfaces between different homogeneous regions. There is therefore no need to discretize and solve equations for the fields in the large empty volume portion of the CATR, unlike when using Finite-Difference Time-Domain (FDTD) or Finite Element Methods (FEM). Using higher-order basis functions allows for the mesh size of the discretized CATR geometry to be as large as two wavelengths, reducing the number of unknowns while enabling fast, efficient solutions. In this paper, a commercial software package that uses MoM with Higher-Order Basis Functions is used to model a CATR that incorporates a blended rolled edge reflector. The results for the reflector and feed model are compared with asymptotic analysis results to show agreement. A realistic feed horn, support structure and RF absorber is then introduced to the model and its performance is also included to predict field distribution in the CATR test zone. Using this field solution the Poynting vector is calculated to visualize the flow of energy in the range and from these results proper RF absorber layout can be designed to ensure optimum test zone performance. It is also shown how feed structure absorber treatment impacts CATR test zone performance.
We examine equivalent multipole sources for the TE/TM-R spherical wavefunctions (SWFs) used in spherical near-field measurements and analysis. The impetus is the understanding of compact sources for wireless power transfer. However, these equivalent multipole sources have other applications including the design of near field probes, especially those with higher orders than typical probes. Equivalent multipole sources for low-order (n<=3) SWFs have been given by Rusch et al. (1986), but with no derivation. A much earlier but less-known work replete with a postulated general mathematical expression for the singular multipole sources has been given by Kennaugh (1959). The multipole source models for the lowest-order SWFs (n<=2, m<=1) given in these two references are identical. This includes the six fundamental electric and magnetic dipoles as well as the TM02-R, TE02-R, TM12 e/o-R, and TE12 e/o-RSWFs. However, careful comparison of the multipole sources given by Rusch et al. and Kennaugh reveals a discrepancy for some of the higher-order SWFs. It is known that the equivalent sources are not unique; that is, there can be more than one equivalent multipole source for a particular SWF. Nevertheless, it appears that some of the multipole source models given by Rusch et al. are incorrect. Specifically, there is a difference in the equivalent multipole source given for the TM22 e-Rspherical wavefunctions given by Rusch et al. and the one given by Kennaugh. Likewise, there is a difference in the multipole sources given for the TE22 e-Rspherical wavefunctions. A SWF decomposition reveals that the source given by Rusch et al. actually produces TM22 e-R with an admixture of a TM44 e-R and TM04-R SWFs, while that given by Kennaugh produces a pure TM22 e SWF. This is shown here using two features in FEKO: (1) construction of an ideal multipole source from electric/magnetic dipoles, and (2) a spherical wavefunction expansion of the fields produced by such a multipole source. More generally, in this paper, corrected multipole sources for the low-order spherical wavefunctions are given along with a discussion of the derivation of these corrected multipole sources.
We examine equivalent multipole sources for the TE/TM-R spherical wavefunctions (SWFs) used in spherical near-field measurements and analysis. The impetus is the understanding of compact sources for wireless power transfer. However, these equivalent multipole sources have other applications including the design of near field probes, especially those with higher orders than typical probes. Equivalent multipole sources for low-order (n<=3) SWFs have been given by Rusch et al. (1986), but with no derivation. A much earlier but less-known work replete with a postulated general mathematical expression for the singular multipole sources has been given by Kennaugh (1959). The multipole source models for the lowest-order SWFs (n<=2, m<=1) given in these two references are identical. This includes the six fundamental electric and magnetic dipoles as well as the TM02-R, TE02-R, TM12 e/o-R, and TE12 e/o-RSWFs. However, careful comparison of the multipole sources given by Rusch et al. and Kennaugh reveals a discrepancy for some of the higher-order SWFs. It is known that the equivalent sources are not unique; that is, there can be more than one equivalent multipole source for a particular SWF. Nevertheless, it appears that some of the multipole source models given by Rusch et al. are incorrect. Specifically, there is a difference in the equivalent multipole source given for the TM22 e-Rspherical wavefunctions given by Rusch et al. and the one given by Kennaugh. Likewise, there is a difference in the multipole sources given for the TE22 e-Rspherical wavefunctions. A SWF decomposition reveals that the source given by Rusch et al. actually produces TM22 e-R with an admixture of a TM44 e-R and TM04-R SWFs, while that given by Kennaugh produces a pure TM22 e SWF. This is shown here using two features in FEKO: (1) construction of an ideal multipole source from electric/magnetic dipoles, and (2) a spherical wavefunction expansion of the fields produced by such a multipole source. More generally, in this paper, corrected multipole sources for the low-order spherical wavefunctions are given along with a discussion of the derivation of these corrected multipole sources.
Modern Aerospace, Naval and Defense platforms are overwhelmed with radiofrequency (RF) signals competing for spectrum. RF co-site interference has become a major problem due to the RF interference from jamming, radio stations nearby, or even from civilian communications such as mobile phones. It can be a problem on military platforms like surface warships, land vehicles, and aircraft where many different RF transmit and receive antennas must share a relatively small space. This can be a communications nightmare in which separate RF systems inadvertently step on each other's signals, causing an RF communications fratricide problem that can also be compounded by intentional or accidental RF jamming. It has become more important than ever to address these issues that arise due to RF co-site interference. In this paper, we present advanced simulation tools for antenna placement, antenna coupling and cosite interference on electrically large naval and air platforms using Altair Feko and Wrap softwares. S-parameter coupling matrix of various antennas (both in-band and out-of-band) are computed using either full-wave solutions such as MoM, MLFMM or using asymptotic methods such as PO, RL-GO and UTD. Alternatively Coupling Loss Matrix, defined as the power ratio between powers at the terminals of the transmitting and receiving antennas can be computed using equivalent sources. S-Parameter matrix or Coupling Loss values are then used to study the parameters of co-site/collocation interference such as inter-modulation products, adjacent channel interference and harmonic interference. Furthermore, we will also discuss the options to mitigate collocation interference by adding appropriate filters.
This paper reports the look through losses witnessed for four hygroscopic indoor material groups, namely, wood, paper, brick, and leather employing the VNA-based Swissto12 MCK terahertz transmission waveguide measurements system. This study focuses on materials encountered widely in the interior of indoor environments. The hygroscopic nature of the chosen materials is studied by measuring the look through losses (i.e., penetration losses) for the dry materials followed by the wet ones in the 0.75–1.1 THz frequency range. The moisture or water content may significantly influence the terahertz wave propagation depending on the free and/or bound water percentage. In addition, this acquired knowledge facilitates the characterization as well as localization of these materials precisely and hence, demands thorough investigations. The chosen material samples along with their frequency-dependent material parameters, thicknesses, and roughness are modeled in CST, which gives a further probe into the interesting hygroscopic effects on penetration losses witnessed for the chosen material groups. Utilizing well-known models such as Bruggeman and Landau-Lifshitz-Looyenga, a 1–60 percent moisture content range is employed in the CST simulations. This paper, however, is the first-ever to investigate the characterization of propagation in hygroscopic indoor materials at THz frequencies. Preliminary measurement results exhibit that the look through losses unexpectedly decline for the chosen material groups in the wet state. These unusual effects on look through losses signify that the bound water molecules as compared to free water content manifest less influence on the THz wave attenuation. All details about the measurement setup and material samples along with both measurement as well as simulation parameters are revealed in the full paper to be presented at the upcoming AMTA symposium.
The three-antenna method is a way of calculating antenna gain without the need for a gain standard. Unlike the comparison or direct methods, the three-antenna method calculates antenna gain solely from measured data and does not require the gain of any of the antennas to be known in advance. As a result, it’s the most favored method in applications where accuracy is of chief concern, like in calibration measurements. However, implementing this method presents additional challenges related to the equipment required, test procedures, and analysis of the resulting data. In this paper, these challenges are addressed with a new methodology used to create a custom script and user interface within the NSI2000 software environment. The script itself is described with the aid of flow charts and then the validation process involving two test campaigns, using both calibrated and non-calibrated standard gain antennas, is given. Following these efforts, the three-antenna method was successfully implemented for the first time in a facility that traditionally only used the gain comparison method. The lessons learned from this project could also prove valuable in understanding the practical considerations concerning the implementation and use of the three-antenna method in any other near-field test range.
As the 5G system becomes today’s main wireless communication service, a MIMO(Multiple-In Multiple-Output) configuration has been considered as an essential feature to provide an unprecedented high date-rate transfer for the wireless service users. Therefore, it is a big concern to design best diversity antennas for a mobile station and base station which are supposed to operate in mm-Wave frequency bands. In addition to the diversity antenna design, optimally deploying the 5G radio frequency system consisting of the MIMO configuration is another big concern to the 5G wireless service providers, because the millimeter Wave (mm-Wave) is expected to lose its transmitting power more abruptly than the previous wireless services. In this paper, the deployment parameters related to the base-station antennas are studiedfor better 5G networkperformance by applying machine learning algorithm. At first, MIMO antennas based on a printed dipole pair are designed both for a mobile platform and a base-station platform by taking into account the MIMO performance factors: envelope correlation coefficient (ECC) and mean effective gain (MEG) at one of the 5G frequency bands (26.5~29.5 GHz). Secondly, the designed antennas are deployed into a urban wireless communication scenario mainly composed of mobile stations, base stations, and buildings. In the urban scenario, the 5G system performance are estimated in terms of received power, signal-to-noise-and-interference ratio, and maximum data rate. Finally, the 5G base-station system is studied to aim at the better system performance by using a machine learning technique which especially suggests optimum antenna parameters for the base-station deployment.
In this paper, a 77 GHz microstrip comb-line antenna array for an automotive RADAR application with a low sidelobe level is proposed. The microstrip technology is used for the antenna due to its low fabrication cost, small size, and easy integration with other microwave circuitry. At very high frequencies such as millimeter waves, the gain of a single element patch antenna is not enough to withstand the RADAR application requirements, hence an array of antennae is beneficial. A The Phased array antenna configuration is needed to have a high gain and low sidelobe level of -20 dB and a beam steering mechanism. The design procedure used here is the implementation of a single comb antenna, that is further realized into a 1 x 10 uniform linear array of a comb line array. It has a gain of 14.81 dB and a sidelobe level of -15 dB. The radiation in the comb antenna is primarily due to the open sides with the lengths of the comb serving as transmission lines. The adjacent combs are placed at the distance of λ in order to co-phase the antenna elements at the desired frequency. Additionally, with an aim of reducing the sidelobe level, Taylor amplitude distribution is used, and the tapered array is designed. This methodology helped to achieve a sidelobe level of -20 dB. The gain of an overall array is increased to 20 dB by realizing the array of 4 x 10. Another requirement of the Automotive Radar is beam steering to accurately detect the target. Butler matrix is a beamforming network chosen to feed the phased array antenna. The proposed antenna array is simulated in Ansys HFSS with Rogers RO 3003 substrate of the thickness of 1.27 mm and has an overall dimension of 9 x 14.96 mm2. The goal of the design of this antenna is to acquire an appropriate radiation pattern with a low side lobe level better than -20dB and achieve beam steering using the Butler matrix to have a phased array configuration. Index Terms— RADAR, Antenna array, Comb line array, Butler Matrix, Phased array.
Hybrid radome-antenna designs can enable novel applications and unique benefits that would be difficult to achieve with standalone radomes and antennas. Examples of such designs are provided which use simple antennas and novel radomes to reduce antenna size and weight, to generate and steer antenna beams without use of complex phased arrays and beam forming networks, and to enable precise direction finding with only two antenna elements.
An antenna’s practical far-field distance can be estimated from the upper bound on the ratio of its gain to quality factor. This upper bound is an infinite series that can be truncated based on the desired accuracy. We investigate the convergence properties of this bounding series. We find that the number of terms required for convergence depends on the antenna’s electrical radius in a way similar to the Wiscombe criterion used in Mie scattering theory. For typical experimental accuracy requirements, such convergence can significantly reduce the effective far-field distance.
In this article, a method is presented which describes how to measure the separate performance parameters of an antenna-receiver system after they have been integrated into one system. The integrated receiver may perform different than the cascaded prediction of the pieces that make up the system due to component interaction. This article develops a method that allows the integrated performance of the individual components (an antenna and a receiver for this discussion) to be measured without disassembly. Using the described method, parameters such as, antenna gain, receiver gain, and receiver effective input noise temperature (correspondingly, receiver noise figure) can be measured. Once the receiver effective input noise temperature is measured, then it is possible to determine the remaining parameters. In the past, the difficulty has been separating out the two noise temperature terms (sky noise and receiver effective input noise). The presented method develops multiple equations which essentially separates out the two terms. Once the two terms have been separated, solving for the others is now possible.
Van Atta Arrays are antennas with uniquely configured beamforming networks (BFNs) that allow for innate retrodirection of incident signals. While useful for a range of applications, their characterization has typically necessitated the use of radar crosssection (RCS) ranges. Our work proposes an alternate method that uses conventional array characterization, specifically element patterns and scattering matrix measurements, to synthesize both bistatic and monostatic RCS patterns for Van Atta arrays. This method is demonstrated theoretically and experimentally first with a cross-polarized dipole array followed by a counterwound octafilar helix antenna array. The benefits of the proposed synthesis method include fast design studies and trades of the Van Atta BFN enabling retrodirective operation. Among other things, this allows for broader access to experimental research on this topic. The significance of the structural radar cross-section is also discussed.
Phased array antennas are often built from sub-arrays with identical or symmetrical layout. At an early project stage, performance verification measurements of the sub-array are valuable to proof the single module design. However, the characteristics of the final antenna are questionable without further processing. This work presents a concept that is based on far-field measurements of a sub-array in a Compact Antenna Test Range (CATR) in conjunction with planar near-field (PNF) processing to synthesize the entire phased array antenna characteristics. The procedure is explained with an example of a dual linear polarized L-band planar phased array antenna for an airborne synthetic aperture radar application. It is shown that the measured sub-array can be complemented by the synthesized twin to evaluate the characteristics of a final antenna that is not yet available in this form. The resulting performance of the synthesized entire phased array is presented and compared with simulations. The presented post-processing method would be beneficial to characterizing radiation patterns of large phased arrays by measuring only sub-arrays in a limited test-zone with any measurement principle.
Unmanned Aerial Systems (UAS), colloquially known as drones, offer unparalleled flexibility and portability for outdoor and in situ antenna measurements, which is especially convenient to assess the performance of systems in their realworld conditions of application. As with any new or emerging measurement technology, it is crucial that the various sources of error must be identified and then estimated. This is especially true here where the sources of error differ from those that are generally encountered with classical antenna measurement systems. This is due to the larger number of mechanical degrees of freedom, and to the potentially less repeatable and controllable environmental conditions. In this paper, the impact of some of these various error terms is estimated as part of an ongoing measurement validation campaign. A mechanically and electrically time invariant reference antenna was characterized at ESAESTEC’s measurement facilities which served here as an independent reference laboratory. The reference results were compared and contrasted with measurements performed outdoors at Quad- SAT’s premises using QuadSAT’s UAS for Antenna Performance Evaluation (UAS-APE). While a direct comparison between the measurement results from ESA-ESTEC and QuadSAT delivers information about the various uncertainties within a UAS-APE system in comparison to classical measurement facilities’ and the validity of such a system for antenna testing, other tests aim at providing an estimation of the impact of each error source on the overall uncertainty budget, thus paving the way towards a standardized uncertainty budget for outdoor UAS-based sites.