Broadband monopulse microstrip antenna array for X‐band monopulse tracking

Abstract

In this study, a broadband planar multilayer monopulse antenna at the X‐band for monopulse tracking applications is presented. A monopulse comparator has been designed using four hybrid ratrace for feeding the radiating elements of the antenna. Each radiating part of the monopulse antenna consists of 4 × 4 electromagnetically coupled microstrip antenna array. To achieve circular geometry as well as better side‐lobe level (SLL), a hybrid feeding technique is used in radiating antenna array by adding a few elements in series at the end elements of the parasitic layer of a 4 × 4 corporate fed array. The prototype has been fabricated, tested and measured results are compared with simulated results. The simulated impedance bandwidth for |S11| ≤ −10 dB is 21% (8.6–10.6 GHz). A measured peak sum beam gain of 24.4 dBi has been obtained. Measured SLL of <−15 dB has been achieved in both elevation and azimuth planes along with a null depth of <−35 dB for difference patterns in both the planes. The radiation pattern is symmetrical in both the planes with half‐power beamwidth nearly equal to 9.0°.

High‐directive monopulse microstrip antenna array for DSRC‐band application

“…The comparative performance of the proposed technique to generate the Δ−pattern with those reported in the reference is given in Table 5. It can be observed that the proposed array is a single port, low‐profile, simple geometry, easy feed network, and has a deep null depth at direction, as compared to other reported methods 7‐16 . The Δ−pattern of proposed technique reflects a good agreement with respect to the other works.…”

Digital beam forming methods for variable polarimetric monopulse radar

“…Monopulse is a well-developed technique and an important part of the tracking radar for achieving a high anti-interference ability and obtaining the direction of target through sumdifference patterns [1][2][3][4][5][6][7]. To further suppress the interference in the mainbeam, full polarimetric detection is introduced in the monopulse radar [8][9][10][11][12][13].…”

Ka-band microstrip array antenna with compact series-parallel hybrid strip-line feeding network

“…The commonly used methods for achieving low FSLL performance include adjusting each element's pattern, as in [24], or adjusting the array's excitation distribution [25,26,27,28,29]. In [25] and [27], large-scale co-planar parallel-fed networks were adopted to realize required current coefficients, and the measured FSLL reached approximately −15 dB and −20 dB, respectively. Such a structure may degrade the cross-polarization level, and the air gap used in [25] results in a thick antenna profile.…”

“…In [25] and [27], large-scale co-planar parallel-fed networks were adopted to realize required current coefficients, and the measured FSLL reached approximately −15 dB and −20 dB, respectively. Such a structure may degrade the cross-polarization level, and the air gap used in [25] results in a thick antenna profile. References [13,24] employed a low-profile single-layer microstrip layout, but their edge feed method caused asymmetry of the antenna patterns to some extent.…”