Subarray‐based coherent pulsed‐LFM frequency diverse array for range resolution enhancement

Abstract

Coherent frequency diverse array (FDA) can provide the full spatial illumination with a stable transmit gain by employing a single frequency-shifted waveform. However, the authors find that the range resolution is scaled linearly with the number of elements. In this work, the problem is first quantitatively analysed through mathematical derivation. To solve the issue, a subarray-based coherent FDA transmitting pulsed linear frequency modulation signals is proposed. The essence of the subaperture technique is to partition the transmit antenna array into multiple regular or irregular subarrays, wherein an identical carrier frequency is utilised in each subarray. Meanwhile, distinct carrier frequencies are adopted between subarrays. Moreover, the multi-dimensional ambiguity function is studied to assess the properties including the range resolution, spatial coverage and sidelobe level. Simulation results demonstrate that the proposed approach has superiorities in range resolution enhancement and range sidelobe reduction.

Low‐sidelobe waveform design for integrated radar‐communication systems based on frequency diversity array

“…We employ two subarray-based time-delay methods to reduce the SLL of range. The subarray-based time-delay methods can provide the transmit waveform with a larger time-domain offset than the communication phase [27][28][29].…”

Range‐angle beamforming with frequency diverse array radar using irregular superposed multicarrier approach for target indication

“…Since first proposed in 2006, 1,2 frequency diverse array (FDA) has drawn considerable interests. [3][4][5][6][7] Different from phased array (PA) producing angle-dependent beampattern, FDA generates a range-angle-dependent beampattern by applying tiny frequency offsets across the array elements. Due to its more degrees of freedom (DOF) in the range dimension, FDA provides more capabilities such as parameter estimation [8][9][10] target indication 11 and jamming suppression [12][13][14] in range-angle domains.…”