Low-noise x-band oscillator and amplifier technologies: comparison and status

Abstract

-This study compares the phase noise of different classes of oscillators and amplifiers that work at X-band. Bestin-class results are presented based on recent measurements at NIST. In particular, comparisons are made between mature technologies of multiplied quartz, sapphire dielectric in whispering gallery mode (WGM), and air-dielectric-resonator stabilized RF oscillators in contrast to various configurations of optical electronic oscillators (OEO), cavity-stabilized, and atomstabilized optical-domain oscillators and femtosecond-lasercomb frequency synthesizers. This study also reports the status of classes of low-noise X-band amplifiers, since high-spectralpurity oscillators are constrained by amplifiers to varying degrees.Best-available low-noise X-band commercial amplifiers are compared with new feedforward, feedback, and array-gain test devices. Straight HBT (heterojunction bipolar transistors) and SiGe HBT technologies are compared in terms of phase noise. Results are for an operating frequency of 10 GHz.

Microwave synthesizer using an on-chip Brillouin oscillator

“…These two scaling laws of performance create challenges for compact or integrated microwave and millimeterwave sources, wherein performance (in terms of phase noise at a given offset frequency) steadily degrades with increasing oscillation frequency 4 . As a result, state-of-the-art microwave oscillators are larger, discrete devices based on dielectric resonators 5 . The introduction of optical fibre for long-distance communication had a positive impact on the frequency scaling side of this problem.…”

A novel clipping technique for filtering FM signals embedded in intensive noise

“…However, the purpose and degree of signal clipping for those applications are different from those for considered application. First of all, in the case of proper selection ofξ in (3) we intend to introduce minimal nonlinear distortions in denoised signal; whereas for the task described above [16], pre-distortions are not so crucial and they are desirable sometimes. Second, the proposed clipping technique is focused on the reduction of the distortions caused by some types of noise, e.g., Gaussian noise, Laplacian, and do not consider the interferences which can arise from other communication channels.…”

“…Second, the proposed clipping technique is focused on the reduction of the distortions caused by some types of noise, e.g., Gaussian noise, Laplacian, and do not consider the interferences which can arise from other communication channels. Third, the proposed approach can be realized only by the digital signal processing methods unlike the approaches implemented in analog amplifiers or FM receivers [9,10,16].…”

“…The algorithm described by [14][15][16] is based on the fact that the greatest number of samples has values located near A. Therefore, the distance between order statistics obtained from (15) and (16) will be the smallest near the value A (see for details [15]).…”

“…In particular, clipping is applied to analog amplifiers [16] preceding frequency and phase detectors [1]. The topic of the influence of the distortions caused by the nonlinear elements of the FM receiver where one of the elements is the clipping device has been investigated by Middleton [4].…”