A note on dual demodulator continuous transmission frequency modulation technique

TL;DR

This paper analyzes the limitations of the dual-demodulator continuous time frequency modulation (DD-CTFM) technique, showing that its range resolution remains constrained by signal bandwidth despite claims of improvement.

Contribution

The paper provides a mathematical and simulation-based explanation of why DD-CTFM cannot surpass the bandwidth limitations in practical range resolution.

Findings

Range resolution is limited by signal bandwidth in practice.

Mathematical analysis confirms the limitations of DD-CTFM.

Simulations support the theoretical findings.

Abstract

The range resolution in conventional continuous time frequency modulation (CTFM) is inversely proportional to the signal bandwidth. The dual-demodulator continuous time frequency modulation (DD-CTFM) processing technique was proposed by Gough et al [1] as a method to increase the range resolution by making the output of DD-CTFM truly continuous. However, it has been found that in practice the range resolution is still limited by the signal bandwidth. The limitation of DD-CTFM has been explained using simulations and mathematically in this paper.