Measurement of static and vibration-induced phase noise in UHF thin film resonator (TFR) filters

Measurements of the static phase noise and vibration sensitivity of thin film resonator (TFR) filters operating at 640 MHz and 2110 MHz have been made. They show that the short-term frequency instability of the filters is small, compared to that induced in the oscillator signal by the sustaining stage amplifier PM noise. In-oscillator measurement of filter performance under vibration indicates fractional frequency vibration sensitivities (δf₀/f₀) are on the order of several parts in 10^-9 per g. Because the percentage bandwidth and order (number of poles) of the filters was fairly constant, so was the product of the center frequency and group delay. Thus, the fractional frequency vibration sensitivity of the filters can be alternatively expressed as carrier signal phase sensitivity to vibration. The τ-ω₀ product for the filters that were tested was on the order of 300 radians, so that the equivalent phase sensitivity to vibration was approximately 1 micro-radian per g