James W H Marsh

Title: James W H Marsh: Innovator in Direct Conversion Tuner Technology

Introduction

James W H Marsh is a notable inventor based in Sherwood, OR (US). He has made significant contributions to the field of electronics, particularly in the area of direct conversion tuner technology. With a total of 2 patents to his name, Marsh has demonstrated his expertise and innovative spirit in developing solutions for modern communication systems.

Latest Patents

One of Marsh's latest patents is titled "DC offset correction for direct conversion tuner IC." This invention discloses a method and apparatus for correcting the DC offset caused by self-conversion of the oscillator signal in an RF-to-baseband converter. The circuit includes a subtractor for subtracting an amplified DC offset signal from a filtered mixer signal to generate a corrected signal. Additionally, a baseband amplifier is coupled to the subtractor to receive the corrected signal and generate a baseband output signal. A low-pass filter is also included to generate a DC offset signal representative of the DC offset, while a DC offset amplifier is coupled to both the low-pass filter and the subtractor to produce the amplified DC offset signal.

Another significant patent by Marsh is the "Direct-conversion tuner integrated circuit for direct broadcast satellite television." This invention pertains to a converter for the direct down-conversion of direct broadcast satellite signals, which are essential for digital television. The direct broadcast satellite signal received from the satellite dish is amplified and downshifted within the Low Noise Block (LNB) to a predetermined frequency band, typically in the L-band range of 950 MHz to 2150 MHz. The signal is then transmitted via a coaxial cable to the set-top box unit indoors, where it is directly converted from the received frequency to baseband using a single integrated circuit that comprises a variable gain amplifier (VGA), frequency synthesizer, a quadrature generator, and multiple mixers.

Career Highlights

James W H Marsh is currently associated with Maxim Integrated Products, Inc., where he continues to innovate and contribute to advancements in electronic technologies. His work has been instrumental in enhancing the performance and efficiency of direct conversion tuners, which are critical for modern communication systems.

Collaborations

Marsh has collaborated with several talented individuals in his field, including Martin Tomasz and Scott Lindsey Williams. These collaborations have fostered an environment of innovation and creativity, leading to the development