Abstract
The target of this research is to design and implement an ultra-wideband (UWB) direct-conversion receiver front-end occupied a small area with good performance to cost down. We have designed and implemented an UWB low noise amplifier (LNA), a wideband passive mixer and a UWB receiver front-end with compact sizes. The LNA was implemented in TSMC 0.13 μm CMOS technology and based on the resistive-feedback architecture with bandwidth extension by gate inductive- peaking. The gate inductor with only 0.4 nH is the only coil used in this circuit which extends the bandwidth and lowers the noise at high frequencies of the LNA effectively. The core area of the LNA is 0.031 mm2. The measured bandwidth of the LNA covers UWB 3.1-10.6GHz and within this band the gain is 11-12.4 dB, the NF is 2.7-3.7 dB and S11 < -7.3 dB. The IIP3 measured at 6 GHz is -3.8 dBm. This LNA consumes 14.4 mW from a 1.8 V supply. The wideband passive mixer implemented in TSMC 0.18 μm CMOS technology is composed of a pre-amplifier, mixing switches, and a 1st order active low-pass filter. The core area of this circuit is 0.15 mm2. Measurement results show that the mixer has a 8.4 dB maximum conversion gain, a 3-7 GHz bandwidth, a 13.8-15.8 dB DSB NF within the bandwidth, a 210MHz IF bandwidth, a -0.4 dB IIP3 at 4 GHz, a good port-to-port isolation, and consumes 10.4 mW from a 1.8 V supply. Finally, the UWB direct-conversion receiver front-end composed of a wideband differential LNA and a wideband passive mixer was implemented in TSMC 0.13 μm CMOS technology. We add a center-tapped inductor which provides differential inductive load with only one coil to extend the bandwidth of the gain, NF and input matching. On the other hand, the capacitive-peaking technique is used in the pre- amplifier of the passive mixer to extend the bandwidth of the overall front-end. Only one coil is used in the whole circuit and the core area of the circuit is 0.22 mm2. The circuit simulated with 21-22 dB conversion gain, 3.7-4.2 dB DSB NF within UWB 3.1-10.6GHz and -15.3 dBm IIP3 at 6.6 GHz. Operating at a 1.8 V supply, this circuit consumes 32.8 mW.