The design of a digital frequency discriminator (DFD), commonly found in digital instantaneous frequency measurement (DIFM) receivers, is presented for the frequency band of 2 to 4 GHz, with details of its synthesis, simulations and adjustments. The results presented good agreement when compared with the existing literature.

2-4 GHz digital frequency discriminator (DFD) design for microwave receivers

An introduction for readers with a general technical background to the design and operation of active electronic countermeasure jamming systems intended to negate the effectiveness of radar systems used by the bad guys. Presents both technical and practical aspects of the hardware and software neede

Radar electronic countermeasure system design

A novel structure of microstrip-based instantaneous frequency measurement (IFM) receiver is presented in this paper. The proposed structure employs open-ended resonators as the core part of the receiver. Compact frequency-shifted filters are designed to achieve high-frequency resolution, instead of conventional binary division. To overcome the reliability issues that conventional binary division has in high-bit IFMs, we introduce a novel complementary filter design, which leads to a highly reliable and robust system design for IFMs. The proposed structure is simulated by Advanced Design System (ADS) and fabricated on Rogers Ro4003 substrate with 8-mil thickness. There is a good agreement between simulation and measurement results. According to the measurement results, the measured root mean square of frequency error is less than 15 MHz in the S-band. Sensitivity and dynamic range of the proposed receiver are better than −65 dBm and 70 dB, respectively.

A High Frequency Resolution Successive-Band Shifted Filters Architecture for a 15-bit IFM Receiver

The paper is concerned with small devices designed for the monitoring of the electromagnetic space. The presented device determines the angle of arrival AOA and the frequency of the received microwave signal. It covers the angular segment of the space, and works within the frequency band of 500 MHz width. It contains three element antenna array, direction finding DF channel and instantaneous frequency measurement IFM channel. Such a structure performs the so called single-pulse phase method of direction of signal arrival estimation. The experimental version of the device worked in conjunction with the personal computer. This set has been successfully used for recognition of signals emitted by a remote electromagnetic sources working within the L band. The device's architecture and results of experiments are presented.

http://ieeexplore.ieee.org/iel5/9380/29804/01358523.pdf

Small passive direction finding and IFM device

This paper presents the design, parameters and results of measurements 6-bits IFM receiver for L band. The device is a complete solution, including limiting amplifier, trigger circuit and a circuit detecting whether a given frequency is out of band (OOB). This receiver is based on one microwave frequency discriminator.

Instantaneous Frequency Measuring Receiver for L band

This article refers to high resolution digital frequency discriminators DFDs. An interesting structure of the microwave phase discriminator MPD was described. It has been built in microstrip technique onto single substrate. The power splitting network was equipped with additional wideband phase shifter. It was done in order to shape DFD characteristics. Thanks to design of each of the discriminator's microwave components and carefully worked out evaluation algorithm, an 11-bit frequency resolution was achieved. The accuracy of the manufactured discriminator is better than /spl plusmn/0.6 MHz over the frequency range of 0.76-1.27 GHz.

H. Gruchala

Papers

11-bit digital frequency discriminator for the P/L band