Ka-Band Vector Reflectometer Based on Simple Phase-Shifter Design

Sensitivity analysis of a single-port vector reflectometer with a wideband phase-shifter

“…At higher frequencies, such off-the-shelf phase-shifters are difficult to find or do not exist all together [8]. So, a novel electronically-controlled phase-shifter at Ka-band (26.5 -40 GHz) was developed in [8] and improved in [9] by making it wideband. The design of this phase-shifter is based on placing a number of minimally-perturbing PIN diode-loaded slots on a waveguide wall.…”

“…These phase-shifters suffered from drawback that can potentially degrade measurement uncertainty. The X-band phase-shifter had insertion loss as high as 8dB and the Ka-band phase-shifters did not provide sufficient phase shifts [8], [9]. This paper presents a sensitivity analysis of a general oneport electronic phase-shifter based wideband reflectometer system.…”

Compact Ka-Band One-Port Vector Reflectometer Using a Wideband Electronically Controlled Phase Shifter

“…On the other hand, VNAs designed based on noncoherent detection schemes estimate the magnitude and phase of the desired signal using power measurements resulting in a relatively simple and inexpensive system [4], [5]. In [6] and [7], novel designs of single-port, low-cost, and portable VNAs, operating in X-band (8.2-12.4 GHz) and at 35.5 GHz in the Ka-band (26.5-40 GHz), were discussed, respectively. The design approach is based on the idea that, by properly phase shifting a reflected signal measured at the aperture of a waveguide and measuring the corresponding standing-wave voltage(s) at a single location along the waveguide, one is able to recover the magnitude and phase of reflection coefficient referenced to the waveguide aperture.…”

“…The current approach eliminates the need for mechanical movement of the detector or the use of several detectors which, in turn, need to be characterized and calibrated to effectively produce similar detection characteristics. In contrast to perturbation two-port approach [8], the proposed technique in [6] and [7] requires neither a scalar network analyzer nor attenuation to the reflected signal. Also, compared to methods such as those reported in [9], this method eliminates the requirement for a multiport hybrid junction.…”

“…An accurate, single-frequency, and electronically controlled phase shifter was successfully designed at 35.5 GHz, using p-i-n diode-loaded nonresonant slots placed along the length of a section of a Ka-band rectangular waveguide [7]. This paper extends the design concept introduced in [7] and incorporates novel design steps to realize an integrated, compact, accurate, and wideband one-port Ka-band vector reflectometer or VNA.…”