Intercept of Frequency Agile Signals with Nyquist Folding Receiver Using Binary Phase Shift Keying as the Local Oscillator

Abstract

Planar end-fire arrays can be used in airborne radar applications for forward and rear vision. The purpose of this work is to demonstrate the viability of constructing end-fire arrays with good bandwidth and front-to-back (f/b) ratio. The array so constructed must be extendable to a large number (possibly >1 000) of elements depending on the platform. In this work, starting from a basic S-band 2×2 array, arrays with higher number of elements have been studied through simulations such as 4×4, 4×8, and 2×16 configurations. An end-fire array comprising 4×8 elements (uniformly excited) has been successfully fabricated and tested giving a f/b ratio of 15 dB, and directivity 15 dB and an array comprising 4×8 elements excited by coefficients of Chebyshev polynomials has been simulated which gives a f/b ratio of 25 dB and similar directivity. Beam steering simulations show that the 4×8 array can be steered to ±25 degrees with acceptable side lobe levels.

An improved local oscillator modulation of modulated sampling scheme for multiple mono-pulse radar signals reconstruction

“…The analysis of step 1 and step 2 of the OMP algorithm is like the analysis of (13). Focusing on the kth NZ, it yields (25) θ PLFM (m) = πµ 0 mod (mT ADC , T LO ) 2 Similar to the analysis in ( 14) and according to (28), the result of , y in the k th NZ is approximately expressed as: (29), the DTFT result is also employed to approximate the DFT result, and the PLFM modulation part in (29) should be investigated to guarantee step 2 of the OMP algorithm returns the atom in the correct NZ under the completely frequency aliasing condition.…”

Estimation of both Nyquist zone index and code rate for BPSK radar signal intercepted by Nyquist folding receiver

“…In order to process the NYFR output easier, the synchronous NYFR structure with a simplified LOS has been designed [9]. In addition, other designs of the LOS modulation type have been investigated [10, 11].…”

Spectral reconstruction of signals from periodic nonuniform subsampling based on a Nyquist folding scheme

“…Rather in the reference [ 19 ], the NYFR architecture is analyzed based on the RIP and block RIP; then, the output signal is recovered by block CS algorithm. Meanwhile, the signal detection and parameter estimation algorithms are studied in references [ 20 , 21 ]. In this paper, we will give the spectral reconstruction algorithm of periodic nonuniform subsampling based on this architecture.…”