Dual-band receiver using passive six-port down-conversion technique suitable for multi-standards and SDR applications

In this paper, a receiver topology using passive microwave network was investigated. A dual-band wireless receiver, which is capable of working for multiple standards over multiple communication bands was designed and tested. The system was implemented at both WiMAX standards (2.4 GHz and 3.6 GHz). The input and local oscillator input were generated using a signal generator, the analog-to-digital conversion was accomplished using power detection diodes and a four-channel oscilloscope, and the signal processing was performed using Matlab. The created system was able to successfully down convert binary phase shift keying, quadrature phase shift keying, 8 phase shift keying and 16 phase shift keying modulated digital signals. The measured SNDR values were equal to 24 dB and 27 dB at the carrier frequencies 2.4 GHz and 3.6 GHz respectively for signal with QPSK modulation and 5 MHz bandwidth.