New structure for a six-port reflectometer in monolithic microwave integrated-circuit technology

Abstract

Abstract-This paper presents a new structure for a six-port reflectometer which due to its simplicity can be implemented very easily in monolithic microwave integrated-circuit (MMIC) technology. It uses nonmatched diode detectors with a high input impedance which are placed around a phase shifter in conjunction with a power divider for the reference detector. The circuit has been fabricated using the F20 GaAs process of the GEC-Marconi foundry and operates between 1.3 GHz and 3.0 GHz.Index Terms-Diode detector, integrated circuit, monolithic microwave integrated-circuit (MMIC), phase shifter, power divider, six-port reflectometer, S-parameter measurement.

A novel six-port circuit based on four quadrature hybrids

“…Various six-port circuits have been proposed and implemented with distributed transmission lines, lumped elements, or a mixture of both [2][3][4] and [8][9][10][11][12][13]. For CMOS SPRs, only lumped elements are possible due to dimension constraints, even though distributed transmission line SPRs are conceptually straightforward to design with little power loss.…”

A new robust method for six-port reflectometer calibration

“…The reflection coefficients measured with the new SPR after this calibration were compared to the reflection coefficients measured with a commercial network analyzer. The maximum absolute difference between the measured values 3 was 0.02 between 1.6 GHz and 2.6 GHz and 0.04 between 1.3 GHz and 3.0 GHz 4 for loads distributed over the whole Smith chart [13].…”

“…The method described here has been used to calibrate a newly developed SPR in GaAs MMIC technology [13], which works between 1.3 GHz and 3.0 GHz. The integrated diode detectors were linearized at 2.0 GHz using the method described in [14] with the correction function given in [15].…”

“…Therefore, by substituting various linear combinations of and (like , etc.) for in (12) and applying (13) to the solution of the corresponding systems of linear equations, the required additional estimates for the extrema of can be obtained. Once the minima and maxima of to have been found, and may be calculated as in [6] and [4] by noting that from (9) to (11) In these equations, the minus signs have to be used if for the corresponding in (9) to (11), i.e., if the origin, , and , respectively, are positioned outside the circle formed by the loads with constant .…”

A new methodology for in situ calibration of a neural network-based software sensor for S-parameter prediction in six-port reflectometers

“…Thus, linear approximation of the diode response around the work frequency is developed in Refs. [8,18,19] or in Ref. [6], where a temperature dependent corrector factor is added for minimizing the error for a wide bandwidth.…”