Determining gas absorption line from separate and alternating RF signals

摘要

A method to detect a gas absorption line that includes alternately transmitting and sweeping two radio frequency (RF) signals through an absorption cell, wherein the two RF signals are transmitted at different frequencies separated by a range and are swept across a span of frequencies in a microwave and millimeter wave regions of a frequency spectrum. Receiving the RF signals by a receiver and analyzing the received signals by a closed loop system for relative absorption by a gas due to an absorption line of the gas in the span of the swept frequencies. Detecting the absorption line of the gas when the two RF signals straddle the gas absorption line and the relative absorption by the two RF signals is equal.

主权项

1. A method to detect a gas absorption line, comprising:
transmitting and sweeping two separate and alternating radio frequency (RF) signals from a signal generator through an absorption cell containing a gas, including transmitting the two alternating RF signals at different frequencies separated by a constant range, and including sweeping the two alternating RF signals across a span of frequencies in microwave and millimeter wave and THz regions of a frequency spectrum; receiving the RF signals from the absorption cell by a receiver; analyzing the received RF signals by a closed loop system for relative absorption by the gas due to an absorption line of the gas in the span of the swept frequencies; and detecting the absorption line of the gas when the two received RF signals straddle the gas absorption line and the relative absorption by the two received RF signals is equal.