Mixer circuitry having a semiconductor body formed therein mixer circuitry having an oscillator having a heterojunction bipolar transistor and a mixer having a Schottky diode. The heterojunction transistor has a collector region formed in one portion of doped layer of the semiconductor body and the diode...http://www.google.de/patents/US6046486?utm_source=gb-gplus-sharePatent US6046486 - Heterojunction bipoplar mixer circuitry
