Design and Development of C + Ku Band Shared Aperture Monopulse Antenna

This paper presents a design of dual-band microstrip /waveguide shared aperture monopulse antenna in C+ Ku-band for semi-active seeker application. The proposed antenna is a six-layer configuration which is a first of its kind providing a new idea of two monopulse antennas on same aperture in two different band and is suitable for compound guidance systems. A single layer C-band printed monopulse array with miniaturized series-fed patch array and compact branch-line coupler design is realized on the top of five layer Ku-band monopulse slotted waveguide array antenna. The electrical performance of microstrip patch antenna array with hybrid network in presence of Ku-band slotted array is presented with EM simulation results. Similarly, the simulated performance of Ku-band monopulse slotted waveguide array in presence of microstrip patch antenna array is also presented here. The design approach has been validated and proven with both ANSYS HFSS and CST EM simulation software. A proto unit is developed and is meeting all the technical specifications of both C-band and Ku-band shared microstrip/waveguide monopulse antenna.

I. Introduction

Shared aperture concept can be used to adopt multi-functional capabilities with dual band or multi-band radiating systems which are necessary for modern on-board radar and communication systems. For airborne applications space, weight and antenna mounting for optimal coverage are important. It is required to reduce the number of antennas as minimum as possible by merging the functionality of several antennas into only a single shared aperture antenna. The use of low and high frequency band combinations of antenna has good electrical performance, which effectively improves the versatility of the radar. Shared aperture antennas are capable of wide beam coverage at operating frequency bands, i.e., detection at C-band and tracking at Kuband need to be placed in the same aperture. Dual-band compact monopulse microstrip/ waveguide compound antenna of C -band and Ku band with dual plane monopulse is a novel technology implemented for a dual mode guidance system [1]–[2].