Abstract: A multi-channel RF transmitter system including a magnetic resonance imaging device, a multi-channel RF coil array, a control computer receiving required parameters from a user, producing triggering and clock signals and synthesizing input data required for each channel of RF coil array according to imaging scenario to be realized, an interface control module producing basic band MRI signals according to data from the control computer, a signal modulator and control module for modulating MRI signals produced at the interface control module into radio frequency and distribution to channels, a power/data distribution module distributing the produced signals and required DC power, a RF power amplifier module converting digital signal coming from the power/data distribution module into analog signal, amplifying it and transmitting to members of the coil array, a feedback line for track and correction of any errors in RF signal transmitted to the coil array by the power amplifier module.

Abstract: A method for generating digital, high resolution pulse width modulation (PWM) signals and a digital feedback correction method suited to the method of generation of the digital, high resolution PWM signals intended for using in feed forward systems, feedback systems and combined feed forward system and feedback system are provided.

Abstract: A multi-channel RF transmitter system including a magnetic resonance imaging device, a multi-channel RF coil array, a control computer receiving required parameters from a user, producing triggering and clock signals and synthesizing input data required for each channel of RF coil array according to imaging scenario to be realized, an interface control module producing basic band MRI signals according to data from the control computer, a signal modulator and control module for modulating MRI signals produced at the interface control module into radio frequency and distribution to channels, a power/data distribution module distributing the produced signals and required DC power, a RF power amplifier module converting digital signal coming from the power/data distribution module into analog signal, amplifying it and transmitting to members of the coil array, a feedback line for track and correction of any errors in RF signal transmitted to the coil array by the power amplifier module.

Abstract: An analog input signal (X(n)) is processed by a Peak to Average Ratio Reduction (PARR) block to diminish the difference between peak amplitudes and average amplitudes of the analog input signal (X(n)). After, a distorted signal (h(n)) having low peak to average amplitude ratio, generated at the PARR block output, is processed by a delta sigma modulation (DSM) block converts the distorted signal (h(n)) into a digitally modulated distorted signal (h_dsm(n)) with high signal to noise ratio (SNR). Afterwards, the digitally modulated distorted signal (h_dsm(n)) is corrected and amplified by a Class-D RF power amplifier fed by a feeding signal (env(n)) generated from a digital correction signal (z_dsm(n)). As a result, a digitally modulated signal (y(n)) with high signal to noise ratio (SNR) of the analog input signal (X(n)) is generated at the output of the Class-D RF power amplifier.

Abstract: In the present invention, an analog input signal (X(n)) is processed by a Peak to Average Ratio Reduction (PARR) block to diminish the difference between peak amplitudes and average amplitudes of the analog input signal (X(n)). After, a distorted signal (h(n)) having low peak to average amplitude ratio, generated at the PARR block output, is processed by a delta sigma modulation (DSM) block converts the distorted signal (h(n)) into a digitally modulated distorted signal (h_dsm(n)) with high signal to noise ratio (SNR). Afterwards, the digitally modulated distorted signal (h_dsm(n)) is corrected and amplified by a Class-D RF power amplifier fed by a feeding signal (env(n)) generated from a digital correction signal (z_dsm(n)). As a result, a digitally modulated signal (y(n)) with high signal to noise ratio (SNR) of the analog input signal (X(n)) is generated at the output of the Class-D RF power amplifier.