Low-cost direct 23GHz transceiver for wideband wireless Internet access

This paper describes realization of a low-cost transceiver based on direct modulation and demodulation at 23GHz. The system is designed for bit rates from 34 to 52Mbit/s with shaped OQPSK modulation. Carrier recovery is performed by decision feedback Costas loop with voltage control dielectric resonator oscillator (VCDRO). Transmitter frequency tolerances and VCDRO temperature drift are compensated by high carrier recovery pull in range of 5.2MHz. Complete receiver dynamics from -82 to -20dBm is obtained only by baseband AGC circuitry. All spectrum shaping and interference suppression characteristics are fulfilled by analogue baseband filtering.