Radio frequency mixer

Claim 1

A balanced mixer wherein a matched pair of gallium arsenide diodes is disposed to produce an intermediate frequency signal equal in frequency to the difference, ω I .F., between the frequency of a radio frequency signal and the frequency of a local oscillator signals, such mixer comprising: (a) a hydrid ring havng a first and a second input lead and a first and a second branch arm, the circumference of the hybrid ring being equal to 3λ S /2, where λ S is the wavelength, in the balanced mixer, of the radio frequency signal, the first and second input leads and the first and second branch arms being connected to the hybrid ring at points such that the radio frequency signal and the local oscillator signal, when connected respectively to the first and the second input leads, divide equally between the first and the second branch arms; (b) a first and a second gallium arsenide diode connected, respectively, between a free end of each one of the branch arms and ground, each one of such diodes generating at a first signal having a frequency of 2ω LO , a second signal having a frequency of ω.sub.Σ, where ω LO is the frequency of a local oscillator signal and ω.sub.Σ is the sum of ω LO and the frequency of the radio frequency signal, and a third signal at a frequency of ω I .F., the first, the second and the third signal being directed over printed circuits toward the hybrid ring; and (c) means along the printed circuit for redirecting a portion of the second signal back through each one of the gallium aresenide diodes in phase with the first signal to produce a fourth signal at a frequency of ω I .F. and in phase with the third signal, the sum of the third and the fourth signals being the intermediate frequency signal.