A 256MHz Analog Baseband Chain with tunable Bandwidth and Gain for UWB Receivers A 256MHz analog baseband chain is implemented in 1.2 V 65nm CMOS process. The baseband chain is composed of one fifthorder type I Chebyshev lowpass filter (LPF) and two variable gain amplifiers (VGA) for Ultra wideband (UWB) applications. The LPF is realized in GmC topology for channel selection. AC coupling capacitor and series divider resistors are used to prevent dcoffset and set a suitable common mode voltage. To achieve wide bandwidth and high linearity, an amplifier with enhanced source degeneration is employed in VGA design. Simulation results show that the baseband chain can realize a variable 3dB bandwidth range from 151MHz to 256 MHz with 15MHz step, and the gain range can vary from 20dB to 38dB with 3 dB step. For the overall chain the noise figure (NF) is 11dB at 38dB gain, while the inputreferred noise (IRN) is 2.5 nVvu0027Hz.

Reconfigurable IRUWB Current Mode Switched Receiver for IoT Applications A multiband impulse radio ultrawideband (IRUWB) receiver with lowcomplexity and lowpower architecture is reported in TSMC  0.13mumathrmm  CMOS technology. The receiver is composed of a lowpower differential UWB low noise amplifier (LNA) with high gain and with relatively flat inband noise figure (NF), a squarer and variable gain baseband amplifier. The LNA, squarer and amplifier can be dynamically reconfigured in three different bands. The post layout simulation results of the LNA show a NF lower than 4.5 dB and a gain of 17.7, 17.1, and 17.5 dB for band1, band2, and band3, respectively. The chip area of the IRUWB receiver is  1.5mathrmmmtimes 1mathrmmm . It consumes 15.3 mW from a 1.2 V supply when one LNA branch is active.