A 2 GHz down-converter with a 3 dB bandwidth of 600 MHz using LO signal suppressing output buffer

In recent years, wide-band wireless communication systems such as IMT-2000 for mobile communication and IEEE802.11 standard for W-LAN applications have received considerable attention. These wide-band systems use a channel bandwidth up to many tens of MHz to achieve a high bit-rate data transfer. In receiver front-end for such wide-band systems, a down-converter (D/C) is required to output a wide-band IF signal whose level should be significantly flat within its channel band for sufficient BER. A D/C and other function blocks are also required not to use many external components and additional pins for a highly integrated receiver. This paper describes a single-balanced Gilbert-cell type D/C with a small number of pins, which can output a wide-band IF signal converted from a 2-GHz-band RF signal.