![Integrated switchless programmable attenuator and low noise amplifier](/abs-image/US/2007/05/31/US20070120605A1/abs.jpg.150x150.jpg)
基本信息:
- 专利标题: Integrated switchless programmable attenuator and low noise amplifier
- 申请号:US11698162 申请日:2007-01-26
- 公开(公告)号:US20070120605A1 公开(公告)日:2007-05-31
- 发明人: Klaas Bult , Ramon Gomez
- 申请人: Klaas Bult , Ramon Gomez
- 申请人地址: US CA Irvine 92618-3616
- 专利权人: Broadcom Corporation
- 当前专利权人: Broadcom Corporation
- 当前专利权人地址: US CA Irvine 92618-3616
- 主分类号: H03G3/00
- IPC分类号: H03G3/00
摘要:
An integrated receiver with channel selection and image rejection substantially implemented on a single CMOS integrated circuit is described. A receiver front end provides programable attenuation and a programable gain low noise amplifier. Frequency conversion circuitry advantageously uses LC filters integrated onto the substrate in conjunction with image reject mixers to provide sufficient image frequency rejection. Filter tuning and inductor Q compensation over temperature are performed on chip. The filters utilize multi track spiral inductors. The filters are tuned using local oscillators to tune a substitute filter, and frequency scaling during filter component values to those of the filter being tuned. In conjunction with filtering, frequency planning provides additional image rejection. The advantageous choice of local oscillator signal generation methods on chip is by PLL out of band local oscillation and by direct synthesis for in band local oscillator. The VCOs in the PLLs are centered using a control circuit to center the tuning capacitance range. A differential crystal oscillator is advantageously used as a frequency reference. Differential signal transmission is advantageously used throughout the receiver.