A Microwave Frequency Measurement System Based on Si3N4 Ring-Assisted Mach-Zehnder Interferometer

Abstract

A microwave frequency measurement system based on a ring assisted Mach-Zehnder interferometer (RAMZI) with a large measurement range and high accuracy is proposed and experimentally demonstrated. By using single-sideband modulation, the microwave signal with unknown frequency is converted to an optical sideband signal, which is used to probe the two complementary output optical powers of the ring-assisted Mach-Zehnder interferometer, then a fixed frequency-to-power mapping is established by obtaining a highly linear amplitude comparison function (ACF). High-precision frequency measurement with a root mean square error (RMSE) of less than 30MHz was achieved in a frequency range of 5.2GHz, and relative low-precision frequency measurement with a RMSE of less than 102MHz was achieved in a frequency range of 11GHz. Besides, in order to break the trade-off between measurement range and measurement accuracy, a multi-band measurement method was implemented and frequency measurement range of 5~39 GHz with RMSE lower than 37MHz was achieved.

Photonic Multiple Microwave Frequency Measurement System with Single-Branch Detection Based on Polarization Interference

“…Generally, the photonics-assisted IFM system can be divided into three categories based on frequency-to-power mapping [4][5][6], frequency-to-time mapping [7,8], and frequency-tospace mapping [9][10][11][12][13]. The majority of frequency-to-power mapping systems rely on producing an amplitude comparison function (ACF), which constructs the relationship between the unknown microwave frequency and the optical or electrical power.…”

“…The majority of frequency-to-power mapping systems rely on producing an amplitude comparison function (ACF), which constructs the relationship between the unknown microwave frequency and the optical or electrical power. The ACF can also be built by polarization [4], interferometers [5] or dispersive mediums [6]. A polarization-multiplexing Mach-Zehnder modulator (PM-MZM) and a polarization controller (PC) are jointly used to realize polarization interference based on optical power monitoring with an error of ±0.2 GHz over 4.…”

“…In Ref. [5], a Si 3 N 4 ring-assisted Mach-Zehnder interferometer is used as a frequency discriminator to achieve a high resolution of less than ±0.037 GHz error over 5-39 GHz. These systems are usually adjustable and have simple structure features, but it has the drawback of only measuring single-tone signals.…”