Abstract: A multi-tune filter system and a control system for operating the multi-tune filter system are described herein. The multi-tune filter system is a tunable frequency range filter. Further, the multi-tune filter system is a digitally programmable filter with an adjustable passband between first and second customizable frequency bounds f1, f2.

Abstract: An amplifier and method of canceling distortion in an amplified signal. The amplifier includes a main amplifier operable to receive a main input signal and generate an amplified signal having a main component and an error component. The amplifier also includes a plurality of error correction amplifiers coupled in a feed-forward arrangement to the main amplifier and operable to receive an input signal and to generate a plurality of output signals, each having a main component and an error component. A balancing network is coupled to the main amplifier and to the plurality of error canceling amplifiers. The balancing network isolates a sample of the output signal of the main amplifier, inverts the sample, and combines the sample with the input signal to the error correction amplifiers.

Abstract: An improved transient interference detector and suppressor for an MRI system detects the presence of transient interference in an MRI signal by detecting the envelope of the MRI signal and comparing the rate of change of the envelope to a reference signal. When the rate of change of the envelope exceeds the reference signal, a transient interference detection is made and appropriate action may be taken. When the rate of change of the envelope is less than the reference signal, no transient interference detection is made. The reference signal is set at a level slightly above a level corresponding to the average thermal noise in order to substantially prevent the minor, random fluctuations in the thermal noise from falsely triggering the detection of a transient interference event.

Abstract: An error correction amplifier and method of canceling distortion in an amplified signal. The error correction amplifier includes a main amplifier operable to receive a main input signal and generate an amplified signal having a main component and an error component. The error correction amplifier also includes a second amplifier coupled in a feed-forward arrangement to the main amplifier and operable to receive an input signal and to generate an output signal having a main component and an error component. A balancing network is coupled to the main amplifier and to the second amplifier. The balancing network isolates a sample of the output signal of the main amplifier, inverts the sample, and combines the sample with the input signal to the second amplifier.

Abstract: An error correction amplifier and method of canceling distortion in an amplified signal. The error correction amplifier includes a main amplifier operable to receive a main input signal and generate an amplified signal having a main component and an error component. The error correction amplifier also includes a second amplifier coupled in a feed-forward arrangement to the main amplifier and operable to receive an input signal and to generate an output signal having a main component and an error component. A balancing network is coupled to the main amplifier and to the second amplifier. The balancing network isolates a sample of the output signal of the main amplifier, inverts the sample, and combines the sample with the input signal to the second amplifier.

Abstract: A holder for a piezoelectric crystal wafer comprising a base, a pair of spaced apart leaf springs secured to the base and a seat member secured to the base between the leaf springs. The leaf springs spread outward upon the application of an external force, to permit the placement of a crystal wafer on the seat member and return toward a normal position upon the release of the external force, to resiliently hold the crystal wafer on the seat member.Each leaf spring includes a pair of prongs at the upper end thereof, separated by a slit having a width slightly larger than the thickness of the wafer. An elongated slot is formed in each of the leaf springs and having a width greater than the width of the slit between the prongs. When the crystal wafer is inserted in the holder, the upper part of the wafer is received in the slit of one leaf spring and a side portion of the wafer extends through the slot of the leaf spring.