magnetic tunnel junction (MTJ) devices are emerging as a possible replacement for complementary metal-oxide semiconductors for radio-frequency (RF) signal generation. Advantages include low power consumption, small device area, and large frequency tunability. This paper shows that single devices cannot achieve the necessary noise performance for RF applications. Various coupling mechanisms are ...

The real-time operation of a linac-MRI system will require proper radio frequency (RF) shielding such that the MRI images can be acquired without extraneous RF noise from the linac. We report on the steps taken to successfully shield the linac from the MRI such that the two devices can operate independently of one another. RF power density levels are reported internally and externally to the RF...

An inductively coupled wireless radio frequency (RF) coil has been developed to improve the quality in the magnetic resonance imaging. The wireless coils of a Helmholtz type and a birdcage type were manufactured, and the resonance frequency was tuned at 64 MHz. Several magnetic resonance images were taken on a phantom, on a rabbit’s head and on a human knee joint with the RF coils. The signal t...

Many instruments can be used to measure radio frequency (RF) and microwave power. The most accurate one is a power sensor with a meter. The accuracy of RF and microwave power measurement depends on the accuracy of power sensor calibration. This chapter provides calibration methods of RF and microwave power sensor with system setup, modeling, equations, and analyses in different representations,...

This paper reports result of calculation and experimental realization of an electromechanical system that consists of a high-Q mechanical oscillator parametrically coupled in the manner of a capacitive transducer with a radio frequency (RF) circuit, which is in turn inductively coupled with another RF circuit. The system operates in the resolved sideband regime when the mechanical oscillator's ...

This paper shows how Radio Frequency (RF) communication is possible for implanted medical devices. RF links between implanted medical devices and external monitoring and programming equipment is becoming more common. However, as new RF applications are introduced the battery operating life of the implanted medical device is a concern. This paper describes a technique to prolong battery life. Th...

We report measurements of nonlinear magneto-optical rotation (NMOR) for the D2 line of 87Rb atoms in an antirelaxation-coated vapor cell in the presence of a radio-frequency (rf) field. The experimental NMOR signals as a function of rf field frequency for various rf field powers are compared to a theoretical model based on the density-matrix formalism. The comparison betwe...

Magnetic resonance force microscopy (MRFM) is a novel ultra-sensitive magnetic resonance detection scheme. In this scheme, forces are measured between a magnet-tipped cantilever and on-resonance spins. It has been proposed that this technique could be used to image biomolecules [1]. In order to increase the sensitivity of MRFM, it may become necessary to use radio-frequency (RF), rather than au...