A low-cost 2.4GHz frequency measurement system for microsecond time domain pulses based on Six-Port technology

Start Page
171
End Page
174
Article Number
6986397
Citation
European Microwave Conference: 6986397 (2014)
Contribution to Conference
European Microwave Week 2014: Connecting the Future, EuMW 2014 , EuMC 2014  
Publisher DOI
10.1109/EuMC.2014.6986397
This paper presents a fast responding frequency measurement system based on Six-Port technology being able to determine precisely the frequency of very short time domain pulses of one microsecond and even less in the 2.4 GHz ISM band. By using a delay line the frequency measurement can be reduced to a phase measurement that can be quickly evaluated by the Six-Port network implemented with lumped components. The delay line, currently realized by a SMA cable, is extremely sensitive to temperature variations even in the range of 0.1K due to changes of the effective relative permittivity of the inner insulator. Thus, a temperature compensation method based on reference measurements is proposed and final measurements show that this system can reach a calibrated and temperature compensated error of only a few parts per million (ppm).