pHEMT and mHEMT ultra wideband millimeterwave balanced resistive mixers

Two ultra wideband millimeterwave single balanced resistive mixers utilizing a Marchand balun for the LO-hybrid are simulated, fabricated and characterized for 30-60 GHz in both up and down conversion. Two different versions of the mixer were manufactured in a commercial pHEMT-MMIC and a mHEMT-MMIC process respectively. A measured down conversion loss of approximately 6 to 12 dB over the whole band is obtained for both versions of the mixer with external IF power combining. In spite of the balanced design, the required LO power is quite low, 2 dBm is sufficient for low conversion loss. The LO-RF isolation is excellent, often more than 30 dB for both type of mixers. Low noise figure and high IIP3 figures are obtained. It is also shown that by applying selective drain bias, up to 5 dB improvement of IIP3 can be obtained for the mHEMT mixer with small LO powers.

[1]  Niklas Rorsman,et al.  A symmetrical nonlinear HFET/MESFET model suitable for intermodulation analysis of amplifiers and resistive mixers , 2000 .

[2]  Antonio Tazón,et al.  Resistive FET mixer conversion loss and IMD optimization by selective drain bias , 1999, IMS 1999.

[3]  S. Maas.  A GaAs MESFET Mixer with Very Low Intermodulation , 1987 .

[4]  M. Chongcheawchamnan,et al.  Monolithic resistive mixers for 60 GHz direct conversion receivers , 2000, 2000 IEEE Radio Frequency Integrated Circuits (RFIC) Symposium Digest of Papers (Cat. No.00CH37096).

[5]  Herbert Zirath.  Analog MMICs for millimeterwave applications based on a commercial 0.14 /spl mu/m PHEMT technology , 2000, 2000 Asia-Pacific Microwave Conference. Proceedings (Cat. No.00TH8522).

[6]  H. Zirath,et al.  A novel single device balanced resistive HEMT mixer , 1995, Proceedings of 1995 IEEE MTT-S International Microwave Symposium.

[7]  Herbert Zirath,et al.  A LO-rejecting balanced upconverter for communication systems , 1996, 1996 26th European Microwave Conference.