We describe a 128 GHz electron-spin-resonance spectrometer based on heterodyne detection with double frequency conversion utilizing cryogenic Schottky-diode mixers. Together with other mm-wave components installed into a dilution refrigerator cryostat, the mixers comprise a bridge operating at 1.5 K. A miniature Fabry-Perot resonator is used to detect samples of bulk and surface-adsorbed atomic hydrogen gas at temperatures below 100 mK. The sensitivity is 2 ϫ10 9 spins/Gauss at the excitation power of 20 pW.

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In this paper, we have designed an impulse-based ultra wideband (UWB) radio module for wireless sensor networks (WSN) applications. The UWB radio module includes transceiver block, baseband process unit and power management block. The transceiver block includes Gaussian pulse generator, wideband low noise amplifier (LNA), multiplier, integrator and timing circuits, which use 0.18um, 1P6M CMOS technology. The wideband LNA has a power gain of 10dB and minimum noise figure of 2.7dB. For transceiver block, the power consumption of transmitter is lower than 1mW while the receiver is about 23mW. The liquid-crystal-polymer (LCP)-based System-on-Package (SoP) technology will be used to implement the UWB radio module for low power, low cost and small size.