Reliable, Intelligent, and Design-Independent Digital Frequency Extraction Methodology for High Bit-Count DIFM Receivers

Abstract

Frequency extraction is the principal objective and the major function of wideband instantaneous frequency measurement (IFM) receivers. The conventional IFM receivers with several-bit discriminators exhibit fast frequency extraction, but the accuracy and reliability of the extracted frequency have not been main goals and concerns as desired. Increasing the number of discriminators to have a high bit-count (HBC) IFM receiver raises some challenges in the reliability of the frequency extraction that have not been thoroughly solved before. A rigorous practical solution for calculating and assigning a unique correct frequency corresponding to each binary code in HBC IFMs has not been accomplished yet. This article introduces a novel methodology for fast, reliable, and design-independent frequency extraction that intelligently utilizes digital processing to overcome these challenges in HBC digital IFMs (DIFMs). Moreover, compared to the conventional low bit-count IFM receivers, the frequency accuracy is improved. The design methodology to achieve an accurate functional IFM is very robust concerning deviations such as variations in discriminators frequency response, complete failure of a discriminator path, and runtime environmental influences. The proposed methodology, named as read like in-ready (InReDI), has been tested on the fabricated 2-4-GHz 15-bit IFM receiver. The measurement results prove the promising achievement of 11-MHz average frequency rms error in the full frequency bandwidth of 2–4 GHz and in the full dynamic range of 70 dBm. By employing the creatively developed digital processing for generating and using the code-frequency mapping space (CFMS), the designed and fabricated 15-bit IFM achieves 8.3 million pulses per second.