High performance K- and Q-band quasi-Yagi linear arrays

Both K-band (20 GHz) and Q-band (44 GHz) passive linear arrays using quasi-Yagi antenna elements are presented. No scan-blindness is observed when the beam is steered 55 degrees from broadside for an inter-element spacing of 0.4/spl lambda/ at X-band. Broad bandwidth of 50% is observed at X-band while both K and Q-band arrays demonstrate over 30% bandwidth (VSWR<2). Measured radiation patterns in four-element linear arrays show well-defined endfire main beams with first sidelobe levels better than -12 dB, cross polarization levels better than -15 dB, and array gains of 8-10 dB across the entire operating band.