Abstract: A process for assaying a biological sample includes: receiving a reference sample by an acoustic article including: a resonator including: a substrate; a piezoelectric member; and a phase noise detector; disposing the reference sample on the piezoelectric member; producing a reference phase noise signal; detecting the reference phase noise signal; disposing a biological sample on the piezoelectric member; producing a first biological phase noise signal; detecting the first biological phase noise signal; contacting the biological sample disposed on the piezoelectric member with an antimicrobial agent; producing a second biological phase noise signal; detecting the second biological phase noise signal; and analyzing the first biological phase noise signal, the second biological phase noise signal, and the reference phase noise signal to assay the biological sample.

Abstract: A process for assaying a biological sample includes: receiving a reference sample by an acoustic article including: a resonator including: a substrate; a piezoelectric member; and a phase noise detector; disposing the reference sample on the piezoelectric member; producing a reference phase noise signal; detecting the reference phase noise signal; disposing a biological sample on the piezoelectric member; producing a first biological phase noise signal; detecting the first biological phase noise signal; contacting the biological sample disposed on the piezoelectric member with an antimicrobial agent; producing a second biological phase noise signal; detecting the second biological phase noise signal; and analyzing the first biological phase noise signal, the second biological phase noise signal, and the reference phase noise signal to assay the biological sample.

Abstract: A high spectral purity microwave oscillator is provided. The Oscillator uses an air-dielectric cavity and employs the known carrier-suppression technique. In one embodiment, the oscillator employs a high-Q cavity to self-sustain an oscillating signal formed by feeding back into its input a power-amplified output signal of the cavity in which residual phase noise in the amplifier stages is suppressed. A bandpass filter selects the cavity mode. FIG. 1 illustrates this embodiment. Another embodiment suppresses the noise of a voltage-controlled oscillator whose frequency and power-amplified output interrogates the cavity mode. FIG. 2 illustrates this embodiment.

Abstract: An apparatus and a method for determining the error due to inherent PM and M noise in a noise measurement device. The apparatus is a calibration standard having a high frequency carrier source and a Gaussian noise source. The outputs of both sources are linearly combined by a power summer so that AM and PM noise components are equal at the output terminals of the calibration standard. To carry out the process of calibrating the calibration standard then determining inherent noise in a noise measuring device under test, the calibration standard includes means for switching to output a signal indicative of either the noise floor or a high frequency signal linearly combined with the output of a Gaussian noise source.

Abstract: A phase modulator for use in a two-oscillator phase noise measurement sys is placed in the line from either the reference oscillator or the device under test. The phase modulator couples a small portion of the input signal to an amplitude modulator and phase shifter to shift the small signal by exactly 90 degrees. The small signal portion is then coupled back into the input signal such that small variations in the coupled signal result in phase modulation and not amplitude modulation which would undermine the calibration of the instrument. The phase modulator described can also be used with known devices of many types to correct the added phase noise of components, e.g., power amplifiers. The phase modulator, when used with a given fixed or variable frequency source, also forms a frequency calibration standard in a single portable instrument.

Abstract: A phase modulator for use in a two-oscillator phase noise measurement system is placed in the line from either the reference oscillator or the device under test. The phase modulator couples a small portion of the input signal to an amplitude modulator and phase shifter to shift the small signal by exactly 90 degrees. The small signal portion is then coupled back into the input signal such that small variations in the coupled signal result in phase modulation and not amplitude modulation which would undermine the calibration of the instrument. The phase modulator described can also be used with known devices of many types to correct the added phase noise of components, e.g., power amplifiers.

Abstract: A crystal oscillator, including two crystals of unequal acceleration sensvity magnitude and mounted such that their respective acceleration sensitivity vectors are aligned in an anti-parallel relationship, further includes at least one electrical reactance, such as a variable capacitor, coupled to one of the crystals for providing cancellation of acceleration sensitivities. After the acceleration sensitivity vectors of the two crystals are aligned anti-parallel, the variable capacitor is adjusted until the net or resultant acceleration sensitivity vector of the pair of resonators is reduced to zero. A second electrical reactance, such as a variable capacitor, is utilized as a tuning capacitor for adjusting the oscillator's output frequency to the desired value, while maintaining the cancellation of acceleration sensitivities.