2-18GHz square law detector

[0029] The square-law detector of 2-18GHz described in the present invention works in a zero bias state and includes an input matching network 1, a detector diode 2 and a low-pass filter 3; the circuit uses a standard commercial dielectric substrate (Rogers 4350, 20mil thickness ) manufacturing; the input matching network 1 of the detector must use an appropriate matching network to obtain high voltage sensitivity, so that as much input signal power as possible can enter the diode. In this design, the structure of the ladder impedance transformation and the open circuit The shorted stubs are used as a matching network. The detector diode 2 of the detector uses the P-type Schottky low barrier detector diode SMS7630-079LF of Skyworks, and its series resistance R S =20Ω, junction capacitance C j =0.14pF, the corresponding NEP is better than 1.49pW / √Hz; the low-pass filter 3 of the detector adopts a fan-shaped stub microstrip filter in the form of high and low impedance, becaus...