This paper reports a new compact dual-band axially corrugated profiled horn feed (DBCPH) for prime-focus reflector antenna at C-band (uplink and downlink frequency bands with bandwidth ratio of 1.6). DBPCH consists of one sinusoid profiled section and two internal axial corrugations (internal short-circuited ring slots), for obtaining a multimode horn feed. Such a blended structure is optimized over the specified frequency bands (3.68-3.70 and 5.865-5.915 GHz) to achieve various performance objectives (such as compactness, return loss, polarization purity, etc.). Measured and predicted results show that DBCPH provides better return loss .18.6 dB, low cross-polarization (better than 232 dB), and adequate edge taper at +488 (8.5-11.7 dB) along with compact size (1.3l aperture diameter and 0.88l length at lower frequency). The horn would be used as a feed element for front-fed prime-focus reflector for pencil beam spacecraft antenna application.

This article proposes the waveguide junction for an orthomode transducer (OMT) with ≈35% realized bandwidth in waveguide slot‐coupled configuration employing a profiled taper/branching region. A wideband impedance match is achieved using a new mirror image concept while constructing the profile from a specified mathematical function. Numerical simulation and experimental verification were carried out for the proposed OMT and good agreements are achieved. This modified configuration provides broader bandwidth compared to the conventional waveguide slot‐coupled OMT's (% bandwidth ≈27%) reported till date. The proposed waveguide junction can be used in multi‐frequency, multi‐band high‐performance antennas and feed systems.