Code-modulated embedded test for phased arrays

Greene, Kevin; Chauhan, Vikas; Floyd, Brian

doi:10.1109/vts.2016.7477274

Cited by 11 publications

(6 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In [114,115], a novel calibration technique that employs code-modulated interferometry is proposed for parallel measurements. Moreover, it requires only a simple power squaring detector without the need for a coherent receiver.…”

Section: Parallel and Noncoherent Techniquesmentioning

confidence: 99%

Impact Analysis and Calibration Methods of Excitation Errors for Phased Array Antennas

Gao

Zhang

2021

IEEE Access

View full text Add to dashboard Cite

Phased array antennas have played a very important role in many different areas and applications. It requires precise excitation of each antenna element by various synthesis techniques to obtain desired array pattern features. However, due to reasons such as manufacturing imperfections, component aging, and temperature variation, the realistic antenna element excitation inevitably differs from their expected values in practice. This paper presents a tutorial-like review to deal with excitation errors for phased array antennas. Two kinds of analysis methods, probabilistic methods and interval arithmetic (IA) based methods, are presented to evaluate the effects of excitation errors for phased array antennas. State-ofthe-art calibration methods along with various signal processing techniques are reviewed, their advantages and challenges are discussed in a comparative manner. Some other common errors and open research directions are also presented.INDEX TERMS Phased array antenna, excitation error, interval arithmetic, array calibration.

show abstract

Section: Parallel and Noncoherent Techniquesmentioning

confidence: 99%

Impact Analysis and Calibration Methods of Excitation Errors for Phased Array Antennas

Gao

Zhang

2021

IEEE Access

View full text Add to dashboard Cite

show abstract

“…The phase shifter provides six-bit phase resolution for normal phased-array operation and Cartesian encoding capability for code-modulation. The phase shifter, power combiner and the power detector were designed by Dr. Kevin B. Greene and more details can be found in [Gre17].…”

Section: Four-element Arraymentioning

confidence: 99%

“…The coding can be done by either using the on chip frequency dividers or serial programmable interface (SPI). The chip also features circuitry for built-in-test technique called as Code Modulated Embedded Test, or CoMET [Gre16]. CoMET uses the code-modulated interferometry and BOCP codes to characterize and calibrate the phased array, and is a secondary contribution of this research [Gre16;Hon19].…”

Section: Four-element Arraymentioning

confidence: 99%

PhD Thesis on Code Modulated Interferometric Imaging System using Phased Arrays

Chauhan¹

2021

Preprint

Self Cite

View full text Add to dashboard Cite

CHAUHAN, VIKAS. PhD Thesis on Code Modulated Interferometric Imaging System using Phased Arrays. (Under the direction of Brian A. Floyd.) This work presents techniques which can allow low-cost phased-array receivers to be reconfigured or re-purposed as interferometric imagers, removing the need for custom hardware and thereby reducing cost. Since traditional phased arrays power combine incoming signals prior to digitization, orthogonal code-modulation is applied to each incoming signal using phase shifters within each front-end and two-bit codes. These codemodulated signals can then be combined and processed coherently through a shared hardware path. Once digitized, visibility functions can be recovered through squaring and code-demultiplexing operations. Provided that codes are selected such that the product of two orthogonal codes is a third unique and orthogonal code, it is possible to demultiplex complex visibility functions directly. As such, the proposed system modulates incoming signals but demodulates desired correlations.Firstly, we present the operation of the system, a validation of its operation using behavioral models of a traditional phased array and a benchmarking of the code-modulated interferometer against traditional interferometer using simulation results and sensitivity analysis. Secondly, for the proof of concept with a prototype, we present a simple CMI system operating in the license-free 60-GHz band using a four-element phased-array receiver developed for IEEE 802.11ad (WiGig) and packaged with compact antenna structures. The four-element 60-GHz phased array chip is wire-bonded onto a Rogers-5880 substrate board with on-board slot antennas, and a single 60-GHz output is measured using a power detector. This scalar measurement is then demodulated to obtain the interferometric visibilities.The four-element phased array is thinned to obtain a 13-pixel image and the system is

show abstract

“…Code-modulated embedded test (CoMET) is an alternative solution, proposed in [7], [8], [9], [10], which employs a scalar (i.e., power) detector to extract all elemental vectors in a parallel fashion. Each element's test signature is modulated using the existing phase shifters and then aggregated into a code-multiplexed response.…”

Section: Introductionmentioning

confidence: 99%

Code-Modulated Embedded Test and Calibration of Phased-Array Transceivers

Hong

Chauhan

Schönherr

et al. 2021

IEEE Trans. Microwave Theory Techn.

Self Cite

View full text Add to dashboard Cite

We present methods for built-in test and calibration of phased arrays using code-modulated embedded test (CoMET). Our approach employs Cartesian modulation of test signals within each element using existing phase shifters, combining of these signals into an aggregate code-multiplexed response, downconversion and creation of code-modulated element-toelement "interference products" using a built-in power detector, demodulation of correlations from the digitized interference response, and extraction of amplitude and phase per element using an equation solver. Rotated-axis methodology is discussed for accurate extraction of phase near the original 0/90/180/270 degree axes. Our techniques are demonstrated at board level for both receive and transmit modes using an eight-element 8-16 GHz phased array constructed using ADAR1000 chips from ADI. At 6 GHz, CoMET-extracted gain and phase are accurate to within 0.2 dB and 3 • compared to network-analyzer measurements. We then employ CoMET in a calibration loop to determinate optimum control settings at 6 GHz, outside the 8-16 GHz band for which the array was designed. We achieve seven-bit phase resolution with equalized gain. The root-mean squared gain and phase errors are improved from 0.8 dB and 8 • before calibration to 0.1 dB and 1.7 • after calibration.Index Terms-code-modulated embedded test, CoMET, codemodulated interferometry, phased array, built-in self-test, calibration, phase shifter.

show abstract

Code-modulated embedded test for phased arrays

Cited by 11 publications

References 8 publications

Impact Analysis and Calibration Methods of Excitation Errors for Phased Array Antennas

Impact Analysis and Calibration Methods of Excitation Errors for Phased Array Antennas

PhD Thesis on Code Modulated Interferometric Imaging System using Phased Arrays

Code-Modulated Embedded Test and Calibration of Phased-Array Transceivers

Contact Info

Product

Resources

About