4-Bit, 1 to 4 GHz reconfigurable discriminator for frequency measurement

Abstract

This paper presents a novel 4-bit reconfigurable discriminator for frequency measurement, operating from 1 to 4 GHz. The discriminator is a two-port device used to identify the frequency of an unknown signal by switching between its 4 states. The device is formed by a fixed reference line and a switchable delay line. The device is implemented using microstrip lines and PIN diodes. Simulated and measured results are presented for the four states of the reconfigurable discriminator.

Integrated microwave frequency discriminator with rat-race 3dB hybrids

“…They can be used where precision is not a main requirement but size of device is the more important parameter. Increasing the measurement accuracy using single-function discriminators very similar to those described in 11 was obtained in multi-channel devices containing several delay lines with different electrical lengths 13,14,15 . The so-called quadrature microwave frequency discriminators (QMFD) 1-6, 7, 8 have a higher resolution of frequency measurement, but also a greater complexity of their structures.…”

Reconfigurable Frequency Discriminator Based on Fractal Delay Line

“…At times t0, t1 and t2, the three combined signals have a phase θ01(τ0,τ1), θ02(τ0,τ2) and θ03(τ0,τ3), respectively [3]. Fig.…”

“…Thus, to achieve high resolution, it is necessary to increase the dimensions of the frequency measurement device. To overcome this problem, a reconfigurable frequency discriminator (RFM) is proposed in [3]. The RFM uses four different delay lines, selected using two SP4T diode-switching circuits.…”

“…Apart from being simple and self-similar, these curves have the additional property of approximately filling the same area. Unlike [2,3], in this letter, all interferometers of the device have the same total area.…”

“…In this paper, an RFM using the second iteration of the Hilbert fractal curve is used to create an even more compact device, combining the reconfigurability and space filling advantages observed in [3] and [4,5], respectively. The compact planar device presented in this letter is the first implementation of a fractal based, fixed size, reconfigurable interferometer for frequency measurement.…”