Orthomode transducer for millimeter-wave correlation receivers

B-Pol: detecting primordial gravitational waves generated during inflation

“…Broadband waveguide OMTs are used for the two lower frequencies 45 and 70 GHz. Return loss and isolation of order 20 dB and 50 dB, respectively, have already been achieved at 100 GHz for a 30% bandwidth [26], and 40 and 70 dB at 30 GHz [27].…”

Passive Microwave Feed-Chains for High-Capacity Satellite Communications Systems

“…In other words, the OMT should in fact be described using the four-port scattering matrix shown in Fig. 5.1 (Peverini, et al 2006). An OMT waveguide architecture is conceived so that each of the two degenerate modes at the common port is nominally coupled to one of the two single-mode ports only.…”

“…Besides the increased manufacturing complexity, the presence of these matching structures can limit the power handling capability of the OMT. An alternative solution to obtain broad-band OMTs has therefore been presented in (Peverini, et al, 2006). The core of the device shown in Fig.…”

“…The complete structure is properly designed so that the various coupled and reflected contributions produce a constructive interference (in-phase combination) for the V-signal to port 3. On the contrary, a destructive interference phenomenon is instead exploited to obtain a low-reflection coefficient at both common and coupled ports (Peverini, et al, 2006). The reverse-coupling section and the stepped transition to port 4 should also be designed in order to route the horizontal polarization to port 4 with a low reflection coefficient.…”

Full-Wave Analysis and Design of Broadband Turnstile Junctions

“…1. This microwave network is a dominant component in current orthomode transducers (OMTs) which are present in a great variety of practical applications, such as dual-polarized antenna feed systems, remote-sensing radiometers and radio astronomy receivers [1][2][3][4]. Consequently, recent years have witnessed active research efforts focused on increasing the operation bandwidth of turnstile junctions.…”