Distributions of boundary array test electronics

Abstract

A method and system (65) for measuring a device under test (22) are disclosed. In some embodiments, the measurement system includes a plurality of antennas (12), each antenna removably mounted interior to a chamber (66) in proximity to a wall (68) of the chamber, each antenna being mounted so that the axes of the plurality of antennas point toward a common region of the test volume. The system also includes, for each antenna, first electronic circuitry (80, 82) including at least one of an upconverter (90) and a downconverter (92), the first electronic circuitry being one of exterior to and interior to the chamber and mounted in proximity to the antenna to enable communication between the antenna and the first electronic circuitry via a short radio frequency (RF) cable (78). The system also includes at least one feedthrough connector (116) configured to communicate signals between the interior of the chamber and exterior of the chamber.

Description

TITLE:DISTRIBUTIONS OF BOUNDARY ARRAY TEST ELECTRONICSTECHNICAL FIELD

[0001] This disclosure relates to a method and system for emulating channels in a radio frequency (RF) communication system including systems that operate in the micro-wave and milli-meter wave frequency ranges.BACKGROUND

[0002] United States Patent No. 8,331,869 describes systems and methods for over-the-air performance testing of wireless devices with multiple antennas. This class of system, referred to as a boundary array system, reproduces a radiated near-field environment that appears to the device in the test volume as though it originated in the far field and had the multipath characteristics of a chosen emulated environment.

[0003] FIG. 1 is a typical multiple input multiple output (MIMO) boundary array configuration 10 for a test of a device under test (DUT) 22, showing boundary array antennas 12 in an anechoic chamber 14 with a wireless communication tester 16 connected through a spatial channel emulator 18 and amplifiers 20. Splitters 28 may be interposed between the wireless communication tester 16 and the spatial channel emulator 18. Some configurations require multiple individual channel emulators synchronized together to produce sufficient output channels to drive all of the antenna elements in the chamber.

[0004] The test configuration of FIG. 1 is typically used to evaluate the receiver performance of the DUT 22. When the DUT 22 is a cellular phone, for example, the test configuration of FIG. 1 would evaluate the downlink signal from the base station to the mobile phone. When the DUT 22 is a base station, for example, the test configuration of FIG. 1 would evaluate the uplink signal from the mobile phone to the base station.

[0005] The device under test (DUT) 22 is positioned on a positioner, such as a turntable, within a test volume of the anechoic chamber 14 that is isolated from the environment exterior to the anechoic chamber 14 by RF absorber lined walls, floor and ceiling. In one mode of operation, the array of antennas 12 radiate electromagnetic energy (radio waves) toward the DUT in a varietyof directions. The radiated signals from each of the antennas 12 have various impairments (delay spread, Doppler, interference, etc.) applied through spatial channel emulator 18 to simulate multipath fading in a real world environment.

[0006] The various impairments are introduced into signals received from the wireless communication tester 16 by one or more spatial channel emulators 18. The signal received from the wireless communication tester 16 are digitized and delayed and weighted in amplitude by the spatial channel emulator 18. More particularly, the spatial channel emulator 18 may add multipath delay, delay spread, fading, interference, and other impairments common in typical radiated communication paths, and then converts the result to analog signals and up-converts the result to a radio frequency, RF. Thus, each output of the spatial channel emulators 18 may be the sum of multiple replicas of the input signal delayed and weighted according to a channel model definition, and will vary in time based on a motion definition that models relative motion of the DUT 22 or an intervening reflector. Doppler frequency shift that would arise from relative motion may also be introduced. Interference may also be introduced by adding additive white Gaussian noise (AWGN) or other noise as well as by injecting specific interfering signals. The full panoply of channel effects emulated by the channel emulator are referred to herein collectively as impairments.

[0007] In a typical configuration, the number of inputs to the spatial channel emulator 18 may be different from the number of outputs of the spatial channel emulator 18. Splitters 28 may be interposed between the wireless communication tester 16 and the spatial channel emulator 18. Each output of the spatial channel emulator 18 is amplified by a power amplifier 20 and directed on a path, typically provided by cables, to an antenna 12. The spatial channel emulator emulates a plurality of channels, each channel being associated with a different one of the antennas 12.

[0008] Amplification is required between the spatial channel emulator 18 and the antennas 12 in order to produce sufficient radiated power to be received by the DUT on the downlink and to amplify the weak signals received from the DUT to be well above the receiver sensitivity of the channel emulator on the uplink. The wireless communication tester 16 emulates an end of a radio link opposite the DUT. The uplink is the path of signal propagation from the DUT 22 to the wireless communication tester 16 (these paths not being shown in FIG. 1).

[0009] The wireless communication tester generates signals according to a communication protocol of the DUT. For example, the wireless communication tester 16 may generate transmitsignals that are formatted for long term evolution (LTE) or New Radio (NR) signaling and may receive signals from the DUT that are also formatted for LTE signaling and / or or NR signaling. Other communication protocols, such as Wi-Fi, may be employed by the wireless communication tester 16. Also shown is a communication antenna 24 coupled to a low noise amplifier (LNA) which is connected to the wireless communication tester 16. A purpose of the communication antenna 24 is to provide an alternate, un-faded and potentially low loss communication path between the DUT and the communication tester for signals that are unrelated to the metric being tested on the DUT (e.g., closed loop feedback of a digital error rate during a receiver sensitivity test) in order to maintain the full communication link.

[0010] FIG. 2 is an implementation of one example of an RF spatial channel emulator 18 that includes emulator receivers (vector signal analyzers) 30 and emulator transmitters (vector signal generators) 32 around a digital signal processing channel emulator core 34. In the channel emulator core, each signal may be impaired and added to other signals to produce impaired signals in order to simulate the effects of one or more signals propagating over the air, being reflected off of obstacles such as buildings, and arriving at the DUT with different amplitudes and phases. Doppler shift may also be introduced by the channel emulator core 34.

[0011] Common components of the emulator receivers 30 are shown in FIG. 3. A low noise amplifier 36 receives an RF signal, possibly having a low SNR, and amplifies the RF signal and optionally passes the amplified RF signal to a further amplification stage that includes a variable gain amplifier 38. The amplified RF signal is down-converted in a mixer 40 with a local oscillator (LO) signal from an LO 42 to produce an intermediate frequency (IF) or baseband signal that is filtered by a filter 44, and possibly further amplified by an amplifier 46. The signal output of the amplifier 46 is an analog signal which may be converted to a digital signal by an analog to digital converter (ADC) 48.

[0012] Common components of the emulator transmitters 32 are shown in FIG. 4 that include a digital to analog converter (DAC) 50, a filter 52, and an amplifier 54. The signal that passes through these components may be at baseband or at an intermediate frequency. The signal is then mixed in a mixer 56 with a local oscillator signal from an LO 58. The output of the mixer is an RF signal that may be further amplified by a variable gain amplifier (VGA)60.

[0013] FIG. 5 is a single emulated downlink channel between a wireless communication tester 16 and a DUT 22. (For simplicity, we shall call the direction of propagation of FIG. 5 thedownlink direction). In the downlink, the wireless communication tester 16 generates transmit signals to be received over the air by the wireless device, DUT 22. The transmit signals from the wireless communication tester are routed to the spatial channel emulator 18a by signal routing 62a, which may be, for example, coaxial cables, and switches that would enable switching to calibration paths or other test paths (not shown) in order to provide flexibility to alter the configuration as desired. Note that there may be any number of RF paths between the wireless communication tester 16 and the spatial channel emulator 18 for multiple input multiple output (MIMO) or diversity testing, all of which are combined into a single RF path for each antenna element at the output of the spatial channel emulator 18.

[0014] The spatial channel emulator 18a replicates each signal received from the wireless communication tester 16, impairs each replica in a different way, and combines the impaired replicas to produce an impaired signal of the channel. Note that the applied impairments may simulate multipath effects as well as Doppler shift and other time and frequency dependent effects. The impaired signal output by the spatial channel emulator 18a is an RF signal that is coupled by signal routing 62b to an amplifier 64 to be amplified. The output of the amplifier 64 is routed to the anechoic chamber 14 to the antenna 12 by signal routing 62c. The antenna 12 radiates the impaired signal to the device under test 22. Note that the signals carried by the signal routing, herein referred to collectively as signal routing 62, are RF signals, and thus, may exhibit significant losses.

[0015] FIG. 6 is a single emulated uplink channel between a DUT 22 and a wireless communication tester 16. (For simplicity, we shall call the direction of propagation of FIG. 6 the uplink direction). Signals radiated by the DUT 22 are received by the antenna 12 which converts the electromagnetic radiation (radio waves) to an RF signal which is amplified by a low noise amplifier (LNA) 36. The RF output of the LNA 36 is coupled out of the anechoic chamber 14 to the spatial channel emulator 18b by signal routing 62d. The spatial channel emulator 18b may apply different impairments to replicas of the received RF signal to form impaired signals to simulate a multipath, Doppler- shifted environment. The output of the spatial channel emulator 18b is at least one output signal that is coupled by signal routing 62e to the wireless communication tester 16.

[0016] Note once again that the signal routing 62 carry RF signals, and thus, the signal routing 62 introduce significant losses and dispersion. As with the downlink chain of FIG. 5, in theuplink configuration of FIG. 6, there may be any number of RF paths between the spatial channel emulator 18 and the wireless communication tester 16 for MIMO or diversity testing. The RF paths may be derived from a single RF signal at the input of the spatial channel emulator 18.

[0017] Note that bidirectional channel emulation can be performed with two separate, synchronized spatial channel emulators 18a and 18b or as a single bi-directionally configured unit. Each channel emulator block may also be realized by a plurality of channel emulators, referred to herein collectively as spatial channel emulators 18.

[0018] While the boundary array technique is a powerful mechanism that can theoretically produce any desired RF environment, the capabilities of currently available RF test equipment provide physical, practical, and financial limits to what can be achieved with the system.

[0019] The ability to produce a uniquely correlated spatial distribution within the test volume is governed by the same Nyquist theorem limitations of near-to-far-field conversion, whereby a spherical surface surrounding the DUT should have at least two sampling points (antenna directions) per wavelength along the surface of the sphere. The larger the antenna separation or general RF interactive region on the DUT, the more active antennas are needed in the boundary array in order to produce the proper RF environmental conditions.

[0020] In addition to the physical constraints of the antenna size around the perimeter of the test volume, which forces a larger array diameter as the number of antennas 12 increases, the number of amplifier and channel emulator resources required increases by as much as four times the number of antenna locations. Since each antenna location may be called upon to support two antenna elements in orthogonal polarizations (i.e., a dual polarized antenna), and assuming bidirectional communication, each antenna location requires four amplifiers connected to two channel emulator transmitters and two channel emulator receivers. In addition, for full spherical coverage, the number of required antennas increases as the square of the frequency to be tested multiplied by the maximal radial extent (MRE) dimension of the DUT, i.e. N ( / )2or N ( / 7z)2. where r is the radial dimension, N is the number of antennas, and A is the wavelength.Stated simply, as the test frequency and / or DUT size increases, the number of required antennas increases.

[0021] Since RF spatial channel emulators 18 were originally designed for conducted testing of radio transmitters and receivers, adapting them for use in over-the-air testing conditions requires the addition of amplification to overcome the losses associated with RF cables, antennaefficiencies of both the boundary array antennas 12 and antennas of the DUT 22, and free-space path losses due to the range length. Since the power amplifiers 20 are independent of the power control of the spatial channel emulator 18, they must provide highly linear performance in order to generate the expected power levels within the test volume.

[0022] Likewise, since power control occurs before amplification on the downlink, the desired signal level moves closer to the instrumentation noise floor and then both signal and noise are amplified and injected into the chamber, where the instrumentation noise may become a significant portion of the signal-to-noise ratio (SNR) seen at the DUT receiver. The noise figure of the power amplifier is also added to the noise of the channel emulator and other instrumentation, thereby decreasing the SNR.

[0023] Similarly, on the uplink, the signal received at the boundary array antenna 12 from the DUT 22 is well below the signal level expected at the input to the spatial channel emulator 18, so low noise amplification is required to boost it above the receiver sensitivity of the spatial channel emulator 18. Since cable losses associated with bringing the signal out of the anechoic chamber 14 to the spatial channel emulator 18 input add to the loss, the resulting negative impact on signal to noise ratio is increased.

[0024] Also, bi-directional communication where both downlink and uplink signals are present simultaneously requires the introduction of some form of isolation to ensure that the high power output of the downlink amplifier is not coupled into the highly sensitive input of the lower noise amplifier. Any cross coupling between the two amplifiers can severely degrade system performance and is highly likely to cause damage on the uplink side, either at the amplifier and / or the input to the spatial channel emulator 18b.

[0025] Since conventional spatial channel emulators 18 are large rack mount pieces of test equipment that reside outside the shielded anechoic chamber 14, as the number of antenna locations increases, not only does the range length increase, but the required length of all cables between the spatial channel emulators 18 and amplifiers 20 and the boundary array antennas 12 generally increases by at least n times the increase in radius. While the free-space path loss increases logarithmically with the increase in radius, the loss of an RF cable is a linear function of the cable length. Thus, eventually the cable losses can dominate the losses of the system as the system is scaled up to include more channels.

[0026] Conversely, in suitable instrumentation amplification, there is an upper limit to the output power of a single power transistor, so that increasing the amplification to overcome additional path loss becomes a problem of parallel amplification rather than series amplification, with the associated complexities of combining the power at the output. The result is that the associated size, cost, heat generation, etc. for the larger amplifiers grows exponentially as the linear output power increases. Finally, the number of required RF cables also increases by the same four times the number of probe positions that the amplifiers and channel emulation must increase.

[0027] As to the wireless communication tester 16, the process of generating an RF signal and then tuning and digitizing it in order to perform the channel emulation via the spatial channel emulator 18 introduces additional error and uncertainty into the signals for both uplink and downlink.

[0028] Thus, one problem with existing systems is the RF path loss associated with the distances involved and the amplification required to overcome these losses. The use of existing centralized RF channel emulators designed for conducted testing coupled with the expensive high power amplifiers needed to overcome this path loss results in most of the expense of the amplification being spent to heat up the RF cables due to internal losses.SUMMARY

[0029] Embodiments advantageously provide a method and system for measuring a device under test. In some embodiments, a method of implementing a measurement system is provided.

[0030] In some embodiments, a method of implementing a measurement system includes distributing a electronics of the measurement system to a location in proximity to a wall of the anechoic chamber. In some embodiments, electronics of the measurement system that perform the various functions of the measurement system, such as spatial channel emulation, amplification and RF processing, may be distributed so that some or all of the electronics of the measurement system are located in proximity to a wall of the anechoic chamber. More particularly, the electronics in proximity to the wall of the anechoic chamber may include both exterior electronics and interior electronics or all exterior electronics or all interior electronics. The exterior electronics in proximity to a wall of the anechoic chamber are exterior to the anechoic chamber and the interior electronics in proximity to the wall of the anechoic chamber are interior to the anechoic chamber.

[0031] In some embodiments, a controller is located at a central location that is exterior to the anechoic chamber and connected by cables to the electronics that are in proximity to the wall of the anechoic chamber. The controller may be configured to enable an operator to configure a wireless communication tester which may be in the central location or may be in proximity to the anechoic chamber wall. The controller may also be configured to enable the operator to configure the spatial channel emulators which are preferably located in proximity to the anechoic chamber wall.

[0032] In some embodiments, exterior electronics are removably affixed to the exterior face of the anechoic chamber wall and / or, to an exterior face of a rigid plate that covers an aperture in the anechoic chamber wall. The rigid plate is configured with a feedthrough connector to connect the exterior electronics to one of the interior electronics and an antenna..BRIEF DESCRIPTION OF THE DRAWINGS

[0033] A more complete understanding of embodiments described herein, and the attendant advantages and features thereof, will be more readily understood by reference to the following detailed description when considered in conjunction with the accompanying drawings wherein:

[0034] FIG. 1 is a block diagram of a known uni-directional boundary array measurement system;

[0035] FIG. 2 is a schematic illustration of a known spatial channel emulator for a typical conducted radio test;

[0036] FIG. 3 is a block diagram of common components of an emulator receiver;

[0037] FIG. 4 is a block diagram of common components of an emulator transmitter;

[0038] FIG. 5 is a single emulated downlink channel between a wireless communication tester and a DUT;

[0039] FIG. 6 is a single emulated uplink channel between a DUT and a wireless communication tester;

[0040] FIG. 7 is a block diagram of a distributed channel emulation system for downlink signaling according to principles disclosed herein;

[0041] FIG. 8 is block diagram of an alternative embodiment of a distributed channel emulation system for downlink signaling according to principles disclosed herein;

[0042] FIG. 9A is a block diagram of a distributed channel emulation system for transmitting to the DUT according to principles disclosed herein;

[0043] FIG. 9B is a block diagram of an alternative embodiment of a distributed channel emulation system for receiving from the DUT according to principles disclosed herein;

[0044] FIG. 10A is a block diagram of an alternative embodiment of a distributed channel emulation system for transmitting to the DUT according to principles disclosed herein;

[0045] FIG. 10B is a block diagram of an alternative embodiment of a distributed channel emulation system for receiving from the DUT according to principles disclosed herein;

[0046] FIG. 11 A is a block diagram of an alternative embodiment of a distributed channel emulation system for transmitting to the DUT according to principles disclosed herein;

[0047] FIG. 1 IB is a block diagram of an alternative embodiment of a distributed channel emulation system for receiving from the DUT according to principles disclosed herein;

[0048] FIG. 12A is a block diagram of an alternative embodiment of a distributed channel emulation system for transmitting to the DUT according to principles disclosed herein;

[0049] FIG. 12B is a block diagram of an alternative embodiment of a distributed channel emulation system for receiving from the DUT according to principles disclosed herein;

[0050] FIG. 13 A is a block diagram of an alternative embodiment of a distributed channel emulation system for transmitting to the DUT according to principles disclosed herein;

[0051] FIG. 13B is a block diagram of an alternative embodiment of a distributed channel emulation system for receiving from the DUT according to principles disclosed herein;

[0052] FIG. 14A is a block diagram of an alternative embodiment of a distributed channel emulation system for transmitting to the DUT according to principles disclosed herein;

[0053] FIG. 14B is a block diagram of an alternative embodiment of a distributed channel emulation system for receiving from the DUT according to principles disclosed herein;

[0054] FIG. 15 illustrates a portion of test chamber and 4 antennas mounted in the interior of a test chamber according to principles disclosed herein;

[0055] FIG. 16 is a view of four antennas mounted in the interior of a test chamber according to principles disclosed herein;

[0056] FIG. 17 illustrates an antenna and mounting assembly according to principles disclosed herein;

[0057] FIG. 18 illustrates an exterior wall of a test chamber with rigid plates covering an aperture in the wall of the test chamber according to principles disclosed herein; and

[0058] FIG. 19 illustrates an exterior wall of a test chamber with rigid plates on each of a plurality of panels in an arcuate configuration according to principles disclosed herein.DETAILED DESCRIPTION

[0059] Before describing in detail example embodiments, it is noted that the embodiments reside primarily in combinations of apparatus components and processing steps related to electromagnetic measurement systems for testing devices. Accordingly, the system and method components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present disclosure so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.

[0060] As used herein, relational terms, such as “first” and “second,” “top” and “bottom,” and the like, may be used solely to distinguish one entity or element from another entity or element without necessarily requiring or implying any physical or logical relationship or order between such entities or elements.

[0061] In embodiments described herein, reference will be made to an emulated channel or emulated spatial channel. An emulated channel is a channel that is emulated by an electronic manipulation of signals to emulate the effects of a channel between a first device, such as a base station or wireless radio, and a second device, such as another base station or wireless device. For example, in a real world environment, an RF signal from a base station to a wireless device, such as a cell phone, leaves the base station and bounces off walls of buildings and the ground so that an RF signal will arrive at the wireless device from different directions at different times. Also, if the wireless device is in motion relative to the source or other objects in the environment, the RF signal arriving at the wireless device may be shifted in frequency. This is known as Doppler shift. Note that the term, RF, as used herein encompasses, without limitation, microwave and millimeter wave frequencies.

[0062] Each emulator core described herein can be programmed to introduce impairments in a replica of a signal from the wireless communication tester to produce a signal that emulates the various impairments of an RF signal propagating through a real- world channel. The spatialchannel emulator may also be programmed to emulate Doppler shift. Similar to the channel effects on the downlink RF signals transmitted to the DUT, channel effects on the uplink RF signals received from the DUT may also be emulated. That is, on the uplink, the emulator core may emulate an actual channel between the DUT and a base station by introducing impairments to a signal received from the DUT.

[0063] When reference is made herein to a wireless communication tester or communication tester, it will be understood by persons of ordinary skill in the art that such tester is merely representative of a tester, a reference radio, a digitally emulated radio or another boundary array containing an over-the-air radio communication device. The wireless communication tester is capable of sending and receiving communication signals that, in some embodiments, are according to a communications protocol that is used by the DUT, such as for example a Wi-Fi communication protocol or a 3GPP Long Term Evolution (LTE) protocol.

[0064] Reference to mounting electronic circuitry to a rigid plate or chamber wall may include mounting a package holding or containing the electronic circuitry to the rigid plate or the chamber wall or mounting a circuit board containing the electronic circuitry to the rigid plate or the chamber wall. In some embodiments, this is done by securing the electronic circuitry to a bracket that is secured to the rigid plate or chamber wall. In some embodiments, some electronics can be mounted to an interior side of the chamber wall and / or rigid plate and some electronics can be mounted to an exterior side of the chamber wall / and or rigid plate in proximity to the antenna interior to the chamber. In some embodiments, the wireless communication tester, the RF transmitter and / or receiver, and all electronics therebetween are mounted to the interior side of the chamber wall and / or rigid plate. In some embosiments, the wireless communication tester, the RF transmitter and / or receiver, and all electronics therebetween are mounted to the exterior side of the chamber wall and / or rigid plate. In some embodiments, the exterior electronics may be mounted in proximity to the chamber in a rack that is separate from the chamber but in proximity to the chamber.

[0065] Returning to the drawing figures, FIG. 7A is a block diagram of a boundary array electromagnetic measurement system 65 that includes an anechoic chamber 66 at a remote location that has at least one chamber wall 68 which may be shielded and / or lined on the interior with RF absorber. Although an anechoic chamber is disclosed in the drawing figures and discussed herein, principles disclosed herein may be applied to other types of test chambers, suchas reverberation chambers. Inside the anechoic chamber 66 are multiple antennas 12 disposed about a test volume within which is positioned a device under test (DUT) 22. In a central location 70, a controller 72 is provided to enable an operator to configure various components of the measurement to achieve desired test conditions. In some embodiments, a wireless communication tester 74 may also be located in the central location 70. In some embodiments, the wireless communication tester 74 may output one or more signals that may be fed to multiple channels when signals are being transmitted to the DUT 22. In some embodiments, the wireless communication tester 74 may receive one or more signals from the multiple channels when signals are being received from the DUT 22. Note that although only two channels are shown in the drawing figures, more than two channels may be implemented. For example, a boundary array electromagnetic measurement system 65 may have 8 or more antennas and 8 or more channels. Each multiple channel has associated therewith, local electronics 76, exterior electronic circuitry 80 and an antenna 12. Embodiments constructed according to the principles set forth herein may include more or less than 8 antennas, which may be single or dual-polarized. For example, a ring of 8 antennas 12 may be spaced apart by 45 degrees and mounted to chamber wall(s) 68 or in proximity to chamber wall(s) 68. As another example, a cluster of 2, 4 or 6 antennas may be spaced apart by smaller angles and be located on or in proximity to one or more chamber walls 68.

[0066] In some embodiments, when transmitting signals to the DUT 22, signals that are output by the wireless communication tester 74 may be fed to local electronics 76a and 76b which may be configured to operate in parallel. Likewise, signals that are output by the local electronics 76a and 76b may be delivered to the wireless communication tester 74 when receiving signals from the DUT 22. In some embodiments, the local electronics 76a and 76b are configured to have the same hardware and perform the same functions.

[0067] Cables 78a, 78b carry signals between the local electronics 76a, 76b and the exterior electronic circuitry 80a, 80b that are in proximity to the chamber wall 68. In some embodiments, the signals between the local electronics 76 and the exterior electronic circuitry 80 may be carried by a single cable or on a number of cables that is less than the number of antennas 12.

[0068] FIG. 7B is a block diagram of a boundary array electromagnetic measurement system 65 similar to the boundary array electromagnetic measurement system 65 shown in FIG. 7A. The difference between FIGS. 7A and 7B is the location of the remote electronics. In FIG. 7A, theremote electronics are exterior to the anechoic chamber 66 (exterior electronic circuitry 80). In FIG. 7b, the remote electronics are interior to the anechoic chamber 66 (interior electronic circuitry 82).

[0069] FIG. 8 is a block diagram of another example of a boundary array electromagnetic measurement system 65 wherein the electronics that are in proximity to the chamber wall 68 at the remote location include exterior electronic circuitry 80 and interior electronic circuitry 82 located interior to the anechoic chamber 66. The chamber wall 68 may have feedthrough connectors configured to electrically connect cables on either side of the chamber wall 68.

[0070] FIG. 9A is a block diagram of another example of a boundary array electromagnetic measurement system 65, showing the components for transmitting signals to the DUT 22. In FIG. 9A, each set of local electronics 76 includes an RF to digital converter 84, an emulator core 86 and a first combination 88 of a digital-to-analog converter (DAC), filter and amplifier. The output of the first combination 88 is an analog signal that may be at baseband or IF and is carried by the cables 78 to the interior electronic circuitry 82. The interior electronic circuitry 82 includes a frequency upconverter and amplifier 90. The frequency upconverter upconverts the baseband / IF signal received from the central location 70 to an RF signal and the amplifier amplifies the RF signal. The amplified RF signal may be coupled by a short RF cable to the antenna 12, which radiates the RF signal into the test volume toward the DUT 22.

[0071] FIG. 9B is a block diagram of yet another example of a boundary array electromagnetic measurement system 65 configured to receive and process signals received by the antennas 12 from the DUT 22. The interior electronic circuitry 82 may include, for example, a second combination 92 of an amplifier, a downconverter and a filter. The local electronics 76 may include, for example, an amplifier and analog to digital converter (ADC) (third combination 94), an emulator core 86 and a digital to RF converter 85.

[0072] FIG. 10A is a block diagram of another example of a boundary array electromagnetic measurement system 65 configured for transmitting signals to the DUT 22. In this configuration the first combination 88 of the DAC, filter and amplifier is located in the exterior electronic circuitry 80 and the upconverter and amplifiers 90 are located in the interior electronic circuitry 82. The local electronics 76 include the emulator core 86 and the RF to digital converter 84. FIG. 10B illustrates a boundary array electromagnetic measurement system 65 configured for receiving signals from the DUT 22, where the second combination 92 of the amplifierdownconverter and filter is included in the interior electronic circuitry 82 and the amplifier and ADC are in the exterior electronic circuitry 80. The local electronics 76 may include the emulator core 86 and the digital to RF converter 95. Note that in some embodiments, the interior electronics 90 and / or 92 may be moved to the exterior of the anechoic chamber 66 and be part of exterior electronic circuitry 80 located remote from the central location 70. In some embodiments, the exterior electronics 88 and / or 94 may be moved to the interior of the anechoic chamber 66 and be part of the interior electronic circuitry 82 located remote from the central location 70..

[0073] FIG. 11 A is a block diagram of another example of a boundary array electromagnetic measurement system 65 configured for transmitting signals to the DUT 22. In the embodiment of FIG. 11 A, the emulator core 86 and an RF transmitter 98 are included in the exterior electronic circuitry 80. The RF-to-digital converter 84 is located in the local electronics 76. FIG. 11B illustrates a boundary array electromagnetic measurement system 65 configured to receive signals from the DUT 22. The RF receiver 100 and the emulator core are located in the exterior electronic circuitry 80. The digital to RF converter 85 is located in the local electronics 76. In some embodiments, the exterior electronics 86, 98 and / or 100 may be moved to the interior of the anechoic chamber to be part of interior electronic circuitry 82.

[0074] For example, in the embodiment of FIG. 12A, the emulator core 86 is part of the exterior electronic circuitry 80 and the RF transmitter 98 is part of the interior electronic circuitry 82. FIG. 12B illustrates a boundary array electromagnetic measurement system 65 configured for receiving signals from the DUT 22. The RF receiver 100 is located in the interior electronic circuitry 82 and the emulator core 86 is located in the exterior electronic circuitry 80.

[0075] FIG. 13 A is a block diagram of another example of a boundary array electromagnetic measurement system 65 configured for transmitting signals to the DUT 22. In FIG. 13A, the upconverter and amplifiers 90 are in the interior electronic circuitry 82. The first combination 88 of the DAC, filter and amplifier as well as the emulator core 86 are located in the exterior electronic circuitry 80. FIG. 13B illustrates a boundary array electromagnetic measurement system 65 configured for receiving signals from the DUT 22. In the embodiment of FIG. 13B, the second combination 92 of amplifiers, downconverter and filter are located in the interior electronic circuitry 82. The third combination 94 of amplifier and ADC are located in the exterior electronic circuitry 80. In some embodiments, the exterior electronics 86, 88 and / or 94may be moved to the interior of the anechoic chamber 66 to be part of the interior electronic circuitry 82.

[0076] FIG. 14A is a block diagram of another example of a boundary array electromagnetic measurement system 65 configured for transmitting signals to the DUT 22. FIG. is an 14A, the wireless communication tester 74 is located in the exterior electronic circuitry 80. The emulator core 86, the first combination 88 of DAC, filter and amplifier and the upconverter and amplifiers 90 are all located in the exterior electronic circuitry 80a. FIG. 14B illustrates a boundary array electromagnetic measurement system 65 configured for receiving signals from the DUT 22. In the embodiment of FIG. 14B, the wireless communication tester 74, emulator core 86, the third combination 94 of amplifier and ADC, and the second combination 92 of amplifier downconverter and filter, may all be located in the exterior electronic circuitry 80. In some embodiments, all of the exterior electronics 74, 86, 88, 90, 92 and 94, may be moved to the interior of the anechoic chamber 66 to be part of interior electronic circuitry 82.

[0077] Note that different combinations of electronics such as first combination 88 of DAC, filter and amplifer may have components that are in separate packages and possibly located in separate locations interior to and / or exterior to the anechoic chamber 66, as well as partly located at the central location 70 and partly located at the remote location.

[0078] FIG. 15 illustrates a portion of an anechoic chamber 66 with a chamber wall 68. In the example of FIG. 15, four antennas 12 are shown mounted to a chamber wall 68 that is arcuate. The antennas 12 may be mounted such that they point to a common point in the test volume 102. A positioner 104 is configured to hold a device under test (DUT) (not shown). FIG. 16 is a closer view of the four antennas 12. Note that although 4 antennas 12 are shown, there may be more or less than four antennas 12. For example, there may be as many antennas as there are channels. Each antenna 12 may be removably affixed to a rigid plate 106 by a mount 108 that may be removably affixed to the rigid plate 106. The rigid plate 106 may be removably bolted to the chanber wall 68 by bolts 110 shown in FIG. 17. Each mount 108 may be configured to mount its respective antenna 12 to point an axis of the antenna 12 at a different angle into the test volume 102 of the anechoic chamber 66. In some embodiments, the mount extends from the rigid plate 106 to the antenna 12 at a tilt angle with respect to a normal line that is normal to the plate. In some embodiments, the tilt angle by which the mount 108 tilts determines the direction of the main axis of transmission and reception of the antenna 12 In some embodiments, at least twomounts 108 provide different tilt angles by which the axes of the respective antennas 12 are tilted. In some embodiments, at least two of the mounts 108 are interchangable between rigid plates 106. In other words, in some embodiments, a first mount 108 having a first tilt angle may be mounted on a first rigid plate 106 to point a first antenna axis in a first direction and a second mount 108 having a second tilt angle may be mounted on a second rigid plate 106 to point a second antenna axis in a second direction. In some embodiments, the first tilt angle may be different than the second tilt angle. In some embodiments, the first direction and the second direction are configured to point to a common point within the anechoic chamber 66. In one example, the arcuate chamber wall 68 may comprise panels that are coupled on edges. The panels may be arranged so that an imaginary line perpendicular to the interior face of each panel passes through a common point within the test volume of the anechoic chamber 66.

[0079] FIG. 17 is a front perspective view of an antenna 12, affixed to the mount 108 which is affixed to the rigid plate 106 that is bolted to the chamber wall 68 by bolts 110. In addition, absorbers 112 may be positioned around the mount 108 to provide absorption of RF energy to suppress reflections of RF energy from the chamber wall 68, antenna 12, mount 108 and rigid plate 106. A connector 114 may be provided on the antenna 12 to enable connection of the antenna to exterior electronics with a short RF cable and through a feedthrough connector 116 (shown in FIG. 18) in the rigid plate 106. In the configuration of FIG. 17, interior electronic circuitry 82 may be mounted either to the rigid plate 106 or to the chamber wall 68. In some embodiments, there are no interior electronic circuitry 82 and the electronics for the boundary array electromagnetic measurement system 65 are located exterior to the anechoic chamber 68. At a base of the mount 108 that is removably affixed to the rigid plate 106 is a feedthrough connector 116 (hidden from view in FIG. 17, but shown in FIG. 18). The feedthrough connector 116 is mounted in the rigid plate 106 and connects the interior electronic circuitry 82, if any, or the antenna 12 (if there are no interior electronic circuitry 82) to the exterior electronic circuitry 80 on the exterior side of the chamber wall 68. For a dual polarized antenna there may be two feedthrough connectors 116 in the rigid plate 106.

[0080] Thus, some embodiments may include for each antenna 12, an RF module that includes at least the rigid plate 106 and the mount 108. The mount 108 may be configured such that when the antenna is mounted to the rigid plate 106 by the mount 108, the RF module and antenna can be removed and inserted through the aperture that is coverable by the rigid plate 106. Thus, themount 108 is dimensioned at its base to be smaller than the aperture. In addition, the RF module may include electronics mounted on an interior and / or exterior side of the rigid plate 106. The electronics may be mounted to the rigid plate so that the electronics are removable and insertable through the aperture coverable by the rigid plate 106. The aperture is small enough to be covered by the rigid plate 106 but large enough to allow the RF module and antenna to pass therethrough.

[0081] FIG. 18 shows the exterior side of the chamber wall 68 with two feedthrough connectors 116 mounted in the rigid plate 106. In some embodiments, the rigid plate 106 covers an aperture in the chamber wall 68 that allows the assembly of the antenna 12 and mount 108 to be removed through the aperture in the chamber wall 68. In this way, the assembly may be serviced exterior to the anechoic chamber 66. Also, the location of the exterior electronic circuitry 80 in close proximity to the antenna 12 further facilitates ease of maintenance and repair. Note that the mounting configurations shown in FIGS. 16 and 17 are examples. In some embodiments, the antenna and any interior electronics may be mounted (by brackets or a structure separate from the chamber walls 68 but in proximity to the feedthrough connectors 116 that communicate signals into and / or out of the anechoic chamber 66. In some embodiments, the feedthrough connectors 116 may be mounted directly in a chamber wall 68 and not in a rigid plate 106.

[0082] FIG. 19 hows an exterior view of a plurality of panels 118 forming a chamber wall 68 of an anechoic chamber 66. Panel 118a has one rigid plate 106-1, panel 118b has two rigid plates 106-2 and 106-3, panel 118c has two rigid plates 106-4 and 106-5 and panel 118d has one rigid plate 106-6. Each rigid plate 106 may be removably affixed to their respective panels 118 and have one or more feedthrough connectors 116. The exterior electronic circuitry 80 may be removably affixed to the rigid plates 106 or to a respective panel 118, via brackets 120 having apertures to receive screws or bolts to secure the exterior electronic circuitry 80 to the brackets 120, for example. The exterior electronic circuitry 80 may be connected to a feedthrough connector 116 by a short RF cable. In FIG. 19, the panels 118 may be oriented in an arcuate structure as shown in FIG. 16. Note that the feedthrough connectors 116 are not shown in FIG. 19 but one or more feedthrough connectors 116 may be installed in each of one or more of the rigid plates 106. Similarly, one or more brackets may be mounted to an interior side of the chamber wall 68 and / or rigid plate 106 and used to removably mount interior electronic circuitry 82.

[0083] Thus, in some embodiments, at least a portion of the electronics of a boundary array electromagnetic measurement system are in a remote location affixed to an exterior side of a chamber wall 68 of an anechoic chamber 66 and / or a rigid plate 106 in proximity to an antenna 12 which is interior to the anechoic chamber 66 and / or in the remote location affixed to an interior side of the chamber wall 68 of the anechoic chamber 66 and / or the rigid plate 106. In some embodiments, a rigid plate 106 is configured to cover an aperture in the chamber wall 68 to enable servicing the antenna / electronics assembly from one side of the chamber wall 68. The rigid plate 106 is configured to be removably mounted to the chamber wall 68 of the anechoic chamber 66. The rigid plate 106 has at least one feedthrough connector 116 configured to communicate signals between the interior of the anechoic chamber 66 and the exterior of the anechoic chamber 66. An antenna 12 is mounted to an interior side of the rigid plate 106 by a mount 108 that is configured to aim an axis of the antenna 12 toward a point within a test volume of the anechoic chamber 66. Exterior electronic circuitry 80 is mounted to at least one of an exterior side of the rigid plate 106 and an exterior side of the chamber wall 68 of the anechoic chamber 66. The exterior electronic circuitry 80 includes at least an emulator core 86 configurable to emulate a spatial channel of a plurality of spatial channels.

[0084] The emulator core 86 may be connected to a wireless communication tester 74 that is either included in the exterior electronic circuitry 80 or is located remote from the anechoic chamber 66 and connected by a cable 78 to the emulator core 86. In some embodiments, exterior electronic circuitry 80 includes at least one of an RF receiver 100 and an RF transmitter 98.

[0085] In some embodiments, interior electronic circuitry 82 is removably mounted to the interior side of the rigid plate 106 or an interior side of the chamber wall 68 of the anechoic chamber 66. The interior electronic circuitry 82, if present, may include at least one of an RF receiver 100 and an RF transmitter 98. In some embodiments, the interior electronic circuitry 82 includes an emulator core 86 configured to emulate a spatial channel of the plurality of spatial channels. In some embodiments, the interior electronic circuitry 82 includes a wireless communication tester in communication with the emulator core 86.

[0086] Thus, in different embodiments, the emulator core 86 and the RF transmitter 98 and / or RF receiver 100 may be entirely within the exterior electronic circuitry 80 that is exterior to the anechoic chamber 66 or entirely within the interior electronic circuitry 82 that is interior to the anechoic chamber 66. In some embodiments, the circuitry of the emulator core 86 and / or thecircuitry of the RF receiver 100 and RF transmitter 98 may be distibuted among the exterior and interior electronic circuitries. In some embodiments, the RF transmitter 98 may include an upconverter that is exterior to the anechoic chamber and connected by a short RF cable to an antenna.

[0087] In some embodiments, the antenna 12 that is removably mounted to the rigid plate 106 is a dual-polarized antenna and the rigid plate 106 includes two feedthrough connectors 116, one for each polarization of the dual-polarized antenna 12.

[0088] In some embodiments, the RF transmitter 98 includes a first combination 88 of a digital- to-analog converter (DAC), a filter and an amplifier and upconverter and amplifiers 90. In some embodiments, the RF receiver 100 includes a second combination 92 of an amplifier, down converter and a filter and as well as an analog-to-digital converter (ADC) and amplifier (third combination 94). In some embodiments, these components of the RF transmitter 98 and / or RF receiver 100 may be distributed at least in part among the exterior electronic circuitry 80 mounted to the exterior side of the rigid plate 106 or chamber wall 68 of the anechoic chamber 66 and / or the interior electronic circuitry 82 mounted to the interior side of the rigid plate 106 or chamber wall 68 of the anechoic chamber 66.

[0089] In some embodiments, the first and / or second electronic circuitries are configured to include both an emulator core 86 and a wireless communication tester 74. Each combination of wireless communication tester 74 and channel emulator core 86 may be synchronized with other combinations of wireless communication tester 74 and / or channel emulator core 86.

[0090] It is understood that persons of ordinary skill in the art will know that an anechoic chamber includes RF absorber on the walls, floor and ceiling of the anechoic chamber to absorb RF energy, and know that a reverberation chamber includes bare reflective shield walls, floor and ceiling. Other chambers may be partially lined with absorber. As noted above, the impairment introduced into a signal by the emulator core may include an amplitude weighting, a temporal shift or other impairment. Thus, although embodiments described herein refer to an anechoic chamber, principles disclosed herein may be employed in a reverberation chamber or hybrid chamber.

[0091] Note that although each of the FIGS. 7-14B show only one direction, uplink or downlink, it is understood that persons of ordinary skill in the art will be able to implement both directions simultaneously using isolation circuitry between the antenna 12 and the respective up-convertersand down-converters. Such isolation circuitry may include a diplexer, isolator, or even separate transmit and receive antennas. The particular isolation circuitry may depend upon the type of communication protocol being tested. For example, Wi-Fi may call for one type of isolation circuitry, whereas LTE may call for a different type of isolation circuitry.

[0092] The digital communication used to transfer the real-time streaming waveform between the exterior electronic circuitry 80 or the interior electronic circuitry 82 and the central location 70 may be carried through cables 78 specific to the chosen high speed interface (e.g. MXI-2, HSSI, custom, etc.) or fiber optic cables, thereby eliminating the RF interactions and shielding issues associated with electrical cables. In any of the above implementations, the RF connections between the wireless communication tester 74 and channel emulator core 86 could be replaced by baseband or IF communication or digital information transfer to the DAC 88 or from the ADC 94.According to one aspect, a boundary array electromagnetic test system for use with a chamber enclosing a test volume and having walls is provided. The system includes a plurality of antennas, each antenna removably mounted interior to the chamber in proximity to a wall of the chamber, each antenna being mounted so that the axes of the plurality of antennas point toward a common region of the test volume. For each antenna, first electronic circuitry including at least one of an upconverter and a downconverter is provided exterior to or interior to the chamber. The first electronic circuitry may be mounted in proximity to the antenna to enable communication between the antenna and the first electronic circuitry via a short radio frequency (RF) cable. The system may also include at least one feedthrough connector configured to communicate signals beween the interior of the chamber and exterior of the chamber.

[0093] In some embodiments, the system includes a plurality of rigid plates, each rigid plate of the plurality of rigid plates being removably secured to a wall of the chamber and having an interior side facing an interior of the chamber and having an exterior side facing an exterior of the chamber. An antenna may be removably mounted to the interior side of the rigid plate. Also, first electronic circuitry including at least one of an upconverter and a downconverter is one of exterior to and interior to the chamber and may be mounted to a rigid plate that is removably attached to the chamber wall so that a short RF cable may be used to enable electrical communication between the antenna and the electronics of the system. The rigid plate includes atleast one feedthrough connector mounted in the rigid plate and configured to enable electrical communication of signals beween the interior of the chamber and exterior of the chamber. According to this aspect, in some embodiments, a first antenna is mounted by a first mount configured to aim a first axis of the first antenna at a first angle with respect to a reference plane and a second antenna is mounted by a second mountconfigured to aim a second axis of the second antenna at a second angle with respect to the reference plane. In some embodiments, the first mount and the second mount are removably securable to a same wall of the chamber. In some embodiments, each antenna is mounted to a rigid plate by a mount, each rigid plate being removably secured to a wall of the chamber and configured to cover an aperture in the wall of the chamber.

[0094] In some embodiments, a first mount mounted to a first rigid plate is configured to aim a first axis of a first antenna at a first angle with respect to a reference plane and a second mount mounted to a second rigid plate is configured to aim a second axis of a second antenna at a second angle with respect to the reference plane. In some embodiments, the first rigid plate is in proximity to the second rigid plate and the first rigid plate and the second rigid plate are removably secured to a same wall of the chamber. In some embodiments, a first rigid plate is removably secured to a first wall of the chamber and a second rigid plate is removably secured to a second wall of the chamber. In some embodiments, the first wall is at an acute interior angle with respect to the second wall. In some embodiments, the antennas are mounted by mounts configured to aim axes of the antennas to a same point within the test volume. In some embodiments, a plurality of walls of the chamber are arranged so that the antennas removably mounted to the interior sides of the rigid plates on each wall are aimed to a same point within the test volume. In some embodiments, each of the plurality of rigid plates is positioned on an arcuate wall of the chamber so that antennas removably mounted to interior sides of the rigid plates are positioned in an arc about the test volume. In some embodiments, for each rigid plate, the first electronic circuitry includes an emulator core configurable to emulate a different spatial channel of a plurality of emulated spatial channels. In some embodiments, for each rigid plate, the first electronic circuitry further includes a wireless communication tester configured to communicate with the emulator core. In some embodiments, for each rigid plate, the first electronic circuitry further includes at least one of a radio receiver and a radio transmitter configured to communicate with the emulator core and the antenna that is removably mounted tothe rigid plate. In some embodiments, the system also includes, for each rigid plate, second electronic circuitry removably mounted to one of an interior side of the wall of the chamber and the interior side of the rigid plate, the second electronic circuitry being connected to the antenna removably mounted to the interior side of the rigid plate and connected to the first electronic circuitry via the feedthrough connector. In some embodiments, the second electronic circuitry includes at least one of a radio receiver and a radio transmitter. In some embodiments, the second electronic circuitry includes an emulator core configured to emulate a spatial channel. In some embodiments, each antenna is a dual-polarized antenna and the at least one feedthrough connector includes a first feedthrough connector associated with a first polarization of the dualpolarized antenna and with a second feedthrough connector associated with a second polarization of the dual-polarized antenna. In some embodiments, each of the plurality of antennas are mounted to an arcuate wall of the chamber so that the antennas are positioned in an arc about the test volume.

[0095] According to another aspect, a radio assembly for a boundary array electromagnetic test system is provided. The assembly includes: a rigid plate having a first side and a second side, the rigid plate configured to be removably mounted to a wall of a chamber and to cover an aperture in the wall of the chamber so that the first side of the rigid plate faces an interior of the chamber and the second side of the rigid plate faces an exterior of the chamber. The assembly also includes an antenna removably mounted to the first side of the rigid plate, the antenna being configured to radiate towards a test volume enclosed by the chamber when the rigid plate is removably mounted to the wall of the chamber. The assembly further includes at least one feedthrough connector mounted in the rigid plate and configured to enable electrical communication of signals through the rigid plate. The assembly also includes first electronic circuitry positionable in at least one of the interior and exterior of the chamber and removably mountable to at least one of the wall of the chamber and the rigid plate, the first electronic circuitry having one of an input port and an output port electrically coupled to one of the at least one feedthrough connector, the first electronic circuitry including at least one of: a wireless communication tester configured to process wireless communication signals; and an emulator core configurable to emulate a spatial channel of a plurality of spatial channels.

[0096] According to this aspect, in some embodiments, the first electronic circuitry further includes at least one of a radio frequency, RF, receiver and an RF transmitter. In someembodiments, the assembly includes second electronic circuitry removably mounted to one of the first side of the rigid plate and an interior side of the wall of the chamber, the second electronic circuitry including the at least one of a radio frequency, RF, receiver and an RF transmitter. In some embodiments, the second electronic circuitry further includes the emulator core configurable to emulate the spatial channel. In some embodiments, the antenna is removably mounted to the rigid plate by a mount configured to aim an axis of the antenna toward a point within a test volume of the chamber when the rigid plate is removably mounted to the wall of the chamber. In some embodiments, the assembly includes removable RF absorbing material positionable around the mount to provide absorption of RF energy in a vicinity around the mount. In some embodiments, the mount is removably affixed to one quadrant of the rigid plate and the removable RF absorbing material is removably affixed to the remaining three quadrants of the rigid plate. In some embodiments, the antenna is a dual-polarized antenna and the at least one feedthrough connector includes a first feedthrough connector associated with a first polarization of the dual-polarized antenna and a second feedthrough connector associate with a second polarization of the the dual-polarized antenna.

[0097] It is to be understood that the functions / acts noted in the blocks may occur out of the order noted in the operational illustrations. For example, two blocks shown in succession may in fact be executed substantially concurrently or the blocks may sometimes be executed in the reverse order, depending upon the functionality / acts involved. Although some of the diagrams include arrows on communication paths to show a primary direction of communication, it is to be understood that communication may occur in the opposite direction to the depicted arrows.

[0098] Many different embodiments have been disclosed herein, in connection with the above description and the drawings. It will be understood that it would be unduly repetitious and obfuscating to literally describe and illustrate every combination and subcombination of these embodiments. Accordingly, all embodiments can be combined in any way and / or combination, and the present specification, including the drawings, shall be construed to support claims to any such combination or subcombination.

[0099] It will be appreciated by persons skilled in the art that the present embodiments are not limited to what has been particularly shown and described herein above. In addition, unless mention was made above to the contrary, it should be noted that all of the accompanyingdrawings are not to scale. A variety of modifications and variations are possible in light of the above teachings without departing from the scope of the following claims.

Claims

What is claimed is:

1. A boundary array electromagnetic test system for use with a chamber enclosing a test volume and having walls, the system comprising: a plurality of antennas, each antenna removably mounted interior to the chamber in proximity to a wall of the chamber, each antenna being mounted so that the axes of the plurality of antennas point toward a common region of the test volume; for each antenna, first electronic circuitry including at least one of an upconverter and a downconverter, the first electronic circuitry being one of exterior to and interior to the chamber and mounted in proximity to the antenna to enable communication between the antenna and the first electronic circuitry via a short radio frequency (RF) cable; and at least one feedthrough connector configured to communicate signals beween the interior of the chamber and exterior of the chamber.

2. The system of Claim 1, wherein a first antenna is mounted by a first mount configured to aim a first axis of the first antenna at a first angle with respect to a reference plane and a second antenna is mounted by a second mountconfigured to aim a second axis of the second antenna at a second angle with respect to the reference plane.

3. The system of Claim 2, wherein the first mount and the second mount are removably securable to a same wall of the chamber.

4. The system of any of Claims 1-3, wherein each antenna is mounted to a rigid plate by a mount, each rigid plate being removably secured to a wall of the chamber and configured to cover an aperture in the wall of the chamber.

5. The system of Claim 4, wherein a first rigid plate is removably secured to a first wall of the chamber and a second rigid plate is removably secured to a second wall of the chamber.

6. The system of Claim 5, wherein the first wall is at an acute interior angle with respect to the second wall.

7. The system of any of Claims 4-6, wherein, for each rigid plate, the first electronic circuitry includes an emulator core configurable to emulate a different spatial channel of a plurality of emulated spatial channels.

8. The system of Claim 7, wherein, for each rigid plate, the first electronic circuitry further includes a wireless communication tester configured to communicate with the emulator core.

9. The system of any of Claims 4-8, wherein, for each rigid plate, the first electronic circuitry further includes at least one of a radio receiver and a radio transmitter configured to communicate with the emulator core and the antenna that is removably mounted to the rigid plate.

10. The system of any of Claims 4-9 further comprising, for each rigid plate, second electronic circuitry removably mounted to one of an interior side of the wall of the chamber and the interior side of the rigid plate, the second electronic circuitry being connected to the antenna removably mounted to the interior side of the rigid plate and connected to the first electronic circuitry via the feedthrough connector.

11. The system of Claim 10, wherein the second electronic circuitry includes at least one of a radio receiver and a radio transmitter.

12. The system of Claim 11, wherein the second electronic circuitry includes an emulator core configured to emulate a spatial channel.

13. The system of any of Claims 1-12, wherein each antenna is a dual-polarized antenna and the at least one feedthrough connector includes a first feedthrough connectorassociated with a first polarization of the dual-polarized antenna and with a second feedthrough connector associated with a second polarization of the dual-polarized antenna.

14. The system of any of Claims 1-13, wherein each of the plurality of antennas are mounted to an arcuate wall of the chamber so that the antennas are positioned in an arc about the test volume.

15. A radio assembly for a boundary array electromagnetic test system, the assembly comprising: a rigid plate having a first side and a second side, the rigid plate configured to be removably mounted to a wall of a chamber and to cover an aperture in the wall of the chamber so that the first side of the rigid plate faces an interior of the chamber and the second side of the rigid plate faces an exterior of the chamber; an antenna removably mounted to the first side of the rigid plate, the antenna being configured to radiate towards a test volume enclosed by the chamber when the rigid plate is removably mounted to the wall of the chamber; at least one feedthrough connector mounted in the rigid plate and configured to enable electrical communication of signals through the rigid plate; and first electronic circuitry positionable in at least one of the interior and exterior of the chamber and removably mountable to at least one of the wall of the chamber and the rigid plate , the first electronic circuitry having one of an input port and an output port electrically coupled to one of the at least one feedthrough connector, the first electronic circuitry including at least one of: a wireless communication tester configured to process wireless communication signals; and an emulator core configurable to emulate a spatial channel of a plurality of spatial channels.

16. The assembly of Claim 15, wherein the first electronic circuitry further includes at least one of a radio frequency, RF, receiver and an RF transmitter.

17. The assembly of Claim 16, further comprising second electronic circuitry removably mounted to one of the first side of the rigid plate and an interior side of the wall of the chamber, the second electronic circuitry including the at least one of a radio frequency, RF, receiver and an RF transmitter.

18. The assembly of Claim 17, wherein the second electronic circuitry further includes the emulator core configurable to emulate the spatial channel.

19. The assembly of any of Claims 16-18, wherein the antenna is removably mounted to the rigid plate by a mount configured to aim an axis of the antenna toward a point within a test volume of the chamber when the rigid plate is removably mounted to the wall of the chamber.

20. The assembly of Claim 19, further comprising removable RF absorbing material positionable around the mount to provide absorption of RF energy in a vicinity around the mount.

21. The assembly of Claim 20, wherein the mount is removably affixed to one quadrant of the rigid plate and the removable RF absorbing material is removably affixed to the remaining three quadrants of the rigid plate.

22. The assembly of any of Claims 15-21, wherein the antenna is a dual-polarized antenna and the at least one feedthrough connector includes a first feedthrough connector associated with a first polarization of the dual-polarized antenna and a second feedthrough connector associate with a second polarization of the the dual-polarized antenna.

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