This paper presents a 3-stage differential cascode power amplifier (PA) for 109–137 GHz applications. At 120 GHz the circuit delivers 16.5 dBm saturated output power with 12.8 % power-added efficiency (PAE) without using power combining techniques. The chip was fabricated in 130 nm SiGe BiCMOS technology offering heterojunction bipolar transistors (HBT) with f T /f max of 300/500 GHz. The PA consists of three stages optimized accordingly to the design goals. The first stage operates in class A to provide high gain while the two following stages are biased in class AB and deep class AB in order to increase the efficiency. The circuit draws a maximum current of 100 mA from 3.3 V and 4 V supplies. It occupies only 0.24 mm 2 chip area excluding baluns and bondpads, which makes it attractive for future power combiners. The presented amplifier is suitable for radar applications, that require a high dynamic range.
This paper presents a highly selective integrated dielectric sensor with read-out circuit at 240 GHz in SiGe BiCMOS and back-side etching technology. The sensor features with a resonator to perform bandpass frequency response which varied in accordance to the dielectric change of the sample under test. This variation can be sensed and recorded as the change of output voltage of an integrated 240 GHz IQ receiver. The demonstration of aforementioned function is verified by measuring the output of mixer when a sample is placed over the resonator.
The repeatability of laser proton accelerator is mainly limited by laser plasma interaction, laser target coupling and laser parameter variation. In our recent experiments performed on the Compact Laser Plasma Accelerator at Peking University, gain of proton beams with improved repeatability is demonstrated. In order to control the laser plasma interaction in pre-plasma, cross polarized-wave generation technique is employed to provide a laser pulse with an ultrahigh contrast of 10 −10 A semi-automatic laser and target alignment system with a sensitivity of few microns is employed. The repetition rate of the laser pro-ton accelerator is at the level of 0.1 Hz which is beneficial to decrease laser parameter variation. The shot-to-shot variation of proton energies is about 9% for a level of confidence of 0.95.