PM noise measurement at W-band

Abstract

We report a high-performance 92 to 96 GHz cross-spectrum phase modulation (PM) noise measurement system. Utilizing this system, we measured residual PM noise of several amplifiers, mixers, and frequency multipliers. Data for the measurement system noise floor and the PM noise of W-band components are reported. These results can serve as a temporary benchmark because little or no information is available on the PM noise of components in this frequency range. In addition, we discuss an enhanced-performance frequency synthesizer that operates in the 92 to 96 GHz range. We achieved 5 to 10 dB improvement in the PM noise at 96 GHz compared with our previously designed synthesizer.

A True Optoelectronic Spectrum Analyzer for Millimeter Waves With Hz Resolution

“…The use of many external mixers to cover a certain frequency range increases the complexity of the measurement system, the measurement as a such (requiring the calibration of each individual band [4]) and its cost (even a stand-alone ESA covering up to 90 GHz exceeds by several times the price of a complete photonic CW terahertz system). The use of high harmonics in the mixing process spoils the spectral purity of the spectrum analyzer, given that harmonic mixers basically behave as frequency multipliers, in which the higher the harmonic used, the worse the phase noise performance [5]. Indeed, the use optoelectronic approaches to alleviate this drawback has already been suggested in [5].…”

“…The use of high harmonics in the mixing process spoils the spectral purity of the spectrum analyzer, given that harmonic mixers basically behave as frequency multipliers, in which the higher the harmonic used, the worse the phase noise performance [5]. Indeed, the use optoelectronic approaches to alleviate this drawback has already been suggested in [5]. The reason is that the phase noise scales as the square of the harmonic in electronic frequency multipliers [6], contrasting with the nearly constant phase noise scaling of the the optoelectronic LO presented here, as we will detail in the next subsections.…”

Optically referenced broadband electronic synthesizer with 15 digits of resolution

“…Extension of digital‐photonic synthesis to higher microwave frequencies can be achieved via several different schemes. Electronic multiplication can be employed to convert X‐band signals to the W‐band . While this method is adequate for quartz‐based synthesizers, it would degrade the spectral purity and limit the high‐frequency noise floor of our DPS microwave signals.…”

Digital-photonic synthesis of ultra-low noise tunable signals from RF to 100 GHz

“…Extension of digital-photonic synthesis beyond the bandwidth of the photodetector can be achieved via several different architectures. Electronic multiplication can be employed to multiply X-band signals to the W-band (32,33). While this method is adequate for quartz-based synthesizers, it degrades the spectral purity and limits the high-frequency noise floor (as will be discussed in greater detail below) of our DPS signals.…”