Direct conversion receiver for digital beamforming at 8.45 GHz

Direct conversion receiver for digital beamforming (DBF) at 8.45 GHz for next generation wireless telecommunication is presented. In this proposed system, the quadrature hybrid and tuning circuit are partially constructed by digital techniques for the simplification of hardware. We demonstrate the direct conversion FET second harmonic mixers without DC bias at RF part. We also examine this proposed receiver´s ability to function as a digital beam former. In this result, the digital beam forming can be realize that side lobe level is below -10 dB and the half power beam width is about 60/spl deg/, in case of scanning range is limited /spl plusmn/20/spl deg/ by using this proposed receiver.