Development of a Submillimeter Double-Ridged Waveguide Ortho-Mode Transducer (OMT) for the 385–500 GHz Band

Kamikura, Mamoru; Naruse, Mitsuhide; Asayama, Shin’ichiro; Satou, Naohisa; Shan, Wenlei; Sekímoto, Yutaro

doi:10.1007/s10762-010-9632-1

Cited by 21 publications

(18 citation statements)

References 24 publications

(31 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…12. This time, it is the ALMA Band 8 (385-500 GHz) feedhorn and OMT, which contains a modified Bøifot-style junction employing a doubleridged structure instead of septum and polarization wires [12]- [14]. The basic features which lead to trapped modes are the same -the transition in the horn from circular-to-square which blocks higher-order modes from escaping and the combiner of the two side arms which transitions to a tall, almost-square waveguide before tapering down to the usual rectangular aspect ratio.…”

Section: Alma Band 8 Feedhorn-omtmentioning

confidence: 99%

Graphical Prediction of Trapped Mode Resonances in Sub-mm and THz Waveguide Networks

Morgan

Pan

2013

IEEE Trans. THz Sci. Technol.

View full text Add to dashboard Cite

An analytical method for the visualization and prediction of trapped-mode resonances based on the dimensions of a dispersive microwave network is described. The method as explained is intuitive, easy to implement, and has proven itself to be a useful tool in the avoidance of problems associated with trapped modes prior to fabrication, as well as to correct those problems in designs where this design detail was overlooked.

show abstract

Section: Alma Band 8 Feedhorn-omtmentioning

confidence: 99%

Graphical Prediction of Trapped Mode Resonances in Sub-mm and THz Waveguide Networks

Morgan

Pan

2013

IEEE Trans. THz Sci. Technol.

View full text Add to dashboard Cite

show abstract

“…In order to achieve simultaneous observations of 12 CO J =2-1 (230.538 GHz), 13 CO J =2-1 (220.399 GHz), and C 18 O J =2-1 (219.560 GHz) by using one spectrometer with a bandwidth of 1 GHz, Acqiris AC240, 18 two output signals of the SIS receiver (1st IF) were split to 3 signals, then each of the signal was further down-converted to different frequency in the 2nd IF band, and finally those 3 signals merged and one 0-1 GHz signal which contains the 3 different RF bands was generated in the IF system. 14 In the observation season of 2012, an Orthomode Transducer 19,20 (OMT) for dual-polarization observations was developed and installed to the telescope. The measured characteristics of the OMT were an insertion loss of less than 0.5 dB, return loss of better than 20 dB, and cross polarization coupling of better than 20 dB across 210-250 GHz.…”

Section: Season 2009-2012mentioning

confidence: 99%

Current status and future plan of Osaka Prefecture University 1.85-m mm-submm telescope project

Nishimura

Tokuda

Harada

et al. 2020

Preprint

View full text Add to dashboard Cite

We report the current status of the 1.85-m mm-submm telescope installed at the Nobeyama Radio Observatory (altitude 1400 m) and the future plan. The scientific goal is to reveal the physical/chemical properties of molecular clouds in the Galaxy by obtaining large-scale distributions of molecular gas with an angular resolution of several arcminutes. A semi-automatic observation system created mainly in Python on Linux-PCs enables effective operations. A large-scale CO J =2-1 survey of the molecular clouds (e.g., Orion-A/B, Cygnus-X/OB7, Taurus-California-Perseus complex, and Galactic Plane), and a pilot survey of emission lines from minor molecular species toward Orion clouds have been conducted so far. The telescope also is providing the opportunities for technical demonstrations of new devices and ideas. For example, the practical realizations of PLM (Path Length Modulator) and waveguide-based sideband separating filter, installation of the newly designed waveguide-based circular polarizer and OMT (Orthomode Transducer), and so on. As the next step, we are now planning to relocate the telescope to San Pedro de Atacama in Chile (altitude 2500 m), and are developing very wideband receiver covering 210-375 GHz (corresponding to Bands 6-7 of ALMA) and full-automatic observation system. The new telescope system will provide large-scale data in the spatial and frequency domain of molecular clouds of Galactic plane and Large/Small Magellanic Clouds at the southern hemisphere. The data will be precious for the comparison with those of extra-galactic ones that will be obtained with ALMA as the Bands 6/7 are the most efficient frequency bands for the surveys in extra-galaxies for ALMA.

show abstract

“…In large reflector antenna systems for satellite communications main polarization characteristics are determined by the microwave feed network [8]. Typically, it includes a corrugated horn [9][10][11][12][13][14], a waveguide polarization converter [15][16][17][18][19], a 45° waveguide twist [7,8] and a guidebased orthomode duplexer [20][21][22][23][24]. The dimensions of each specified component of a feed must be optimized for the required operating frequency band.…”

Section: Introductionmentioning

confidence: 99%

Square Waveguide Polarizer with Diagonally Located Irises for Ka-Band Antenna Systems

Piltyay

2021

AEM

View full text Add to dashboard Cite

This article presents the results of development and optimization of a new square waveguide polarizer with diagonally located square irises. The application of suggested geometrical modification of irises form and location instead of a standard wall-to-wall irises configuration allows to exclude 45-degree twists between wideband waveguide polarizer and orthomode transducer of a dual-polarized antenna feed system. In addition, a waveguide polarizer and polarization duplexer can be manufactured by milling technology as two single details, which makes the proposed engineering solution reliable, simple for simulation, development and application. Suggested new polarizer design was developed for the satellite operating Ka-band. It contains 12 irises, which are symmetrically located in the diagonal corners of a square waveguide. Obtained optimal polarization converter provides excellent matching and polarization performance. The maximum level of VSWR is less than 1.04 for both orthogonal polarizations. Values of cross-polarization discrimination are higher than 32 dB in the operating Ka-band. Developed square waveguide polarizer with diagonally located irises can be applied in modern wideband satellite antennas.

show abstract

Development of a Submillimeter Double-Ridged Waveguide Ortho-Mode Transducer (OMT) for the 385–500 GHz Band

Cited by 21 publications

References 24 publications

Graphical Prediction of Trapped Mode Resonances in Sub-mm and THz Waveguide Networks

Graphical Prediction of Trapped Mode Resonances in Sub-mm and THz Waveguide Networks

Current status and future plan of Osaka Prefecture University 1.85-m mm-submm telescope project

Square Waveguide Polarizer with Diagonally Located Irises for Ka-Band Antenna Systems

Contact Info

Product

Resources

About