A 2-32 GHz InAIAs/lnGaAs-lnP HBT CPW distributed amplifier (DA) has been demonstrated which benchmarks the highest bandwidth reported for an HBT DA. The DA combines a 100 iiHz fmax and 60 GHz fT HBT technology with a cascode coplanar waveguide DA topology to achieve this record bandwidth. The cascode CPW I3A demonstrates both design techriiques and technology capability which can be applied to more complex circuit functions such as active baluns for mixers, active c:ombiners/dividers, and low dc powerbroadband amplification at millimeter-wave frequencies.

Here we report on what is believed to be the first Q-band IP3 results of an InAlAsLnGaAs-InP based HBT MMIC linear amplifier. The 3-stage amplifier uniquely combines a "'double-balanced" design topology that incorporates a "current re-use" bias scheme. The amplifier MMIC achieves 15.4 dB of gain, 28.3 dBm of IP3, and a P,,, of 16.2 dBm at 44 GHz. The corresponding outputstage IP3/P, mtio is 5.3 which is the best reported for InP-HBTs at Q-band. The MMIC is a high complexity chip which integrates 15 HBTs and 18 Lange couplers in a 6.2x3.5 mm2 iaea, and is self-biased through 5V while consuming 108 mA. The "current re-use'' enables easier system integration while the "double-balanced" design produces wideband IP3, gain and return-loss performance. This work {demonstrates the promising linearity performance of InP-HBTs and its practical biasing capability which is attractive for Q-band receiver applications such as mm-wave digital radio. IntroductionHigh IP3 amplifiers are needed in mm-wave receiver systems such as Ka-and Q-band digital radio applications. Flor frequencies below 18 GHz, GaAs HBTs [ 13 as well as spiked and pulsed -doped MESFETs [2], [3] have demonstrated record circuit Linearity Figure of Merits (LFOM=IP3/Pd,) which are an order of magnitude better than conventional MESFET amplifiers. However for the mm-wave regime, little has been published on the circuit linearity merits of these technologies. One reason is that