NOVEL SINGLE DEVICE BALANCED RESISTIVE HEMT MIXERS

A family of novel single device balanced resistive HEMT mixers has bee n designed and characterized. The RF is fed through a 180 degrees balu n. The IF is extracted either by a 180 degrees balun or single ended. The main advantages of this type of mixer are that no device pairing i s necessary, since only one HEMT Is used and that no RF and LO groundi ng is necessary. These advantages make the described topology particul arly suitable for microstrip MIC's, MMIC's, crossbar, fin-line and qua si optical mixers. The mixers are designed for RF 17.5-20 GHz, the LO is wideband and the IF is 1-2 GHz. Measurements show a conversion loss of 6 to 8 dB and an LO to RF isolation of up to 37 dB (typically 20 d B).