A novel configuration called the uniplanar MMIC is proposed. It consists of coplanar waveguides, slotlines, air bridges, and lumped circuit elements (GaAs FETs, capacitors, inductors, resistors, etc.), which are integrated on a single side of the GaAs substrate. The uniplanar MMIC has no via holes and no thin polished substrates. As an application of the unipolar MMIC configuration, key monolithic circuits for a 26-GHz full MMIC receiver have been designed and fabricated. The circuits developed, namely, 26-GHz low-noise amplifier, a 26-GHz medium-power amplifier, a 6.5-GHz dual-output voltage-controlled oscillator, 6.5/13-GHz and 13/26-GHz frequency doublers, and a 26-GHz/1-GHz FET mixer, provide improved RF performance with a simplified fabrication process.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>