GHz In Phase Research Articles

Drive beam stabilisation in the CLIC Test Facility 3

The proposed Compact Linear Collider (CLIC) uses a high intensity, low energy drive beam to produce the RF power needed to accelerate a lower intensity main beam with 100 MV/m gradient. This scheme puts stringent requirements on drive beam stability in terms of phase, energy and current. The consequent experimental work was carried out in CLIC Test Facility CTF3. In this paper, we present a novel analysis technique in accelerator physics to find beam drifts and their sources in the vast amount of the continuously gathered signals. The instability sources are identified and adequately mitigated either by hardware improvements or by implementation and commissioning of various feedbacks, mostly beam-based. The resulting drive beam stability is of 0.2°@ 3 GHz in phase, 0.08% in relative beam energy and about 0.2% beam current. Finally, we propose a stabilisation concept for CLIC to guarantee the main beam stability.

Fully integrated 60 GHz transceiver in SiGe BiCMOS, RF modules, and 3.6 Gbit/s OFDM data transmission

A fully integrated transmitter (TX) and receiver (RX) front-end chipset, produced in 0.25 µm SiGe:C bipolar and complementary metal oxide semiconductor (BiCMOS) technology, is presented. The front-end is intended for high-speed wireless communication in the unlicensed ISM band of 9 GHz around 60 GHz. The TXand RX features a modified heterodyne topology with a sliding intermediate frequency. The TX features a 12 GHz in-phase and quadrature (I/Q) mixer, an intermediate frequency (IF) amplifier, a phase-locked loop, a 60 GHz mixer, an image-rejection filter, and a power amplifier. The RX features a low-noise amplifier (LNA), a 60 GHz mixer, a phase-locked loop (PLL), and an IF demodulator. The measured 1-dB compression point at the TX output is 12.6 dBm and the saturated power is 16.2 dBm. The LNA has measured noise figure of 6.5 dB at 60 GHz. Error-free data transmission with a 16 quadrature amplitude modulation (QAM) orthogonal frequency-division multiplexing (OFDM) signal and data rate of 3.6 Gbit/s (without coding 4.8 Gbit/s) over 15 m was demonstrated. This is the best reported result regarding both the data rate and transmission distance in SiGe and CMOS without beamforming.