Microwave–to–millimeter-wave synthesis chain phase noise performance

Abstract

We report on the phase noise measurement of a millimeter-wave synthesis chain developed for a continuous wave (CW) source exhibiting high frequency stability. We quantify the performance of each multiplication stage in terms of phase spectral purity. From the initial cryogenic sapphire oscillator generating 12.97 GHz, a total multiplication factor of eight is applied through two stages to reach a frequency of 103.75 GHz. We find that the chain performance is primarily limited by the phase noise of the initial frequency doubler.

Technical noise in K‐band low‐noise cryogenic amplifier

“…These values are still higher than recent results presented [8] for a room temperature 18–44 GHz amplifier operated at 26 GHz, which featured −112 dBc/Hz at 1 Hz offset.…”

“…With the intensity of noise fluctuations lowered it is now possible to resolve some harmonics of the 4 kHz noise structure. These values are still higher than recent results presented [8] for a room temperature 18-44 GHz amplifier operated at 26 GHz, which featured −112 dBc/Hz at 1 Hz offset. Cryogenic (6.5 K) phase noise measurements are shown in Fig.…”

“…For these measurements the phase bridge was operated in the regime of maximum phase sensitivity, noting that the same results were obtained at the point of minimum amplitude modulation (AM) sensitivity. Corruption of results due to residual AM sensitivity is a major issue for larger offset frequencies and lower noise levels [8] but was not an issue here. The phase‐to‐voltage conversion efficiency of the system, S PD , was redetermined for each measurement as it will depend upon the power incident on the RF port of the mixer.…”

“…The availability of ‘full spectrum’ noise information becomes increasingly elusive as one moves to higher and higher carrier frequencies. Yet, amplifier 1/ F noise ( α 1 ) is of paramount importance in oscillators [5, 6] and related technologies such as frequency synthesis [7, 8]. The physical causes of these fluctuations are technical in origin; it is generally accepted to be due to the DC power biasing of the amplifier [4], hence it is often referred to as technical noise.…”

Optically referenced broadband electronic synthesizer with 15 digits of resolution

“…Single oscillator comparison of the spectral purity of tunable sources room‐temperature synthesizers (markers and solid lines ) as compared to DPS‐derived tunable signals for carrier frequencies (A) 10 MHz, (B) 10 GHz and (C) 100 GHz. Additionally we present the phase noise levels for perfect scaling of a BVA fixed quartz source at 10 MHz and the phase noise for a cryogenic electronic oscillator at 11 GHz and synthesis cryogenic oscillators for derivation of fixed frequency 10 MHz and 103 GHz signals . The phase noise denoted by the red diamonds in (C) is achieved via 6 times electronic multiplication of 15 GHz from a commercial source.…”