Frequency compensated PIN diode attenuator

摘要

An attenuator for signals in the frequency band of 50 to 800 MHz is subject to a range of AGC signal attenuating potentials. The attenuator includes a first attenuating PIN diode connected in series between an input and an output. The opposite ends of the first PIN diode are AC coupled via second and third impedance matching PIN diodes to an AC ground. The first PIN diode exhibits a frequency dependent slope over the wide signal frequency band and the range of AGC potentials. First and second inductors, in the form of metallic foil strips, are connected between the second and third PIN diodes and the AC ground. The foil strips are positioned in close proximity to each other and arranged such that signal currents flow therein in opposite directions to establish a negative mutual coupling coefficient for compensating for the frequency dependent slope of the first PIN diode.