Title :
A square-law microwave transistor detector for wideband radiometers
Author :
Ivanov, S.I. ; Lavrov, A.P. ; Matveev, Y.A.
Author_Institution :
St. Petersburg State Polytech. Univ., St. Petersburg, Russia
Abstract :
This paper describes the design and measurement of a square-law microwave transistor detectors for wideband radiometers. To increase detector dynamic range a negative feedback was used in it. Theoretical analysis and CAD harmonic balance simulation were performed to optimize the detector circuit and find the optimal value of the feedback factor. Two variants of the detector were developed: on BJT and on FET transistors. Experimental hybrid circuits have been realized with discrete transistors, lumped elements and microstrip transmission lines. Results of measurement of detector main characteristics are given: transfer function, tangential sensitivity, dynamic range, frequency response, input VSWR. Dynamic range up to 55 dB was achieved (at 1 dB compression point and 1 kHz video-bandwidth) with flat frequency response up to 4 GHz. These square-law detectors may be used for precision measurements of microwave power, for example in modulation-type wideband microwave radiometers.
Keywords :
bipolar transistors; detector circuits; feedback; field effect transistors; lumped parameter networks; microstrip lines; microwave detectors; radiometers; BJT; CAD harmonic balance simulation; FET transistors; detector circuit; detector dynamic range; discrete transistors; feedback factor; frequency response; hybrid circuits; input VSWR; lumped elements; microstrip transmission lines; microwave power precision measurements; modulation-type wideband microwave radiometers; negative feedback; square-law microwave transistor detectors; tangential sensitivity; transfer function; Detectors; Microwave measurement; Microwave radiometry; Microwave transistors; Radiometers; Temperature measurement; Transistors; dynamic range; microwave radiometer; negative feedback; nonlinearity; square law; transistor detector;
Conference_Titel :
Control and Communications (SIBCON), 2015 International Siberian Conference on
Conference_Location :
Omsk
Print_ISBN :
978-1-4799-7102-2
DOI :
10.1109/SIBCON.2015.7147076
