Design Methodologies of Compact Orthomode Transducers Based on Mechanism of Polarization Selectivity

Sakr, Ahmed A.; Dyab, Walid; Wu, Ke

doi:10.1109/tmtt.2017.2784822

Cited by 17 publications

(6 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…To obtain the coupling length, one can substitute in (2) and (3) by w = 13 mm, m = 0 to get β e and by m = 1 to get β o at 13 GHz. Then substituting β e and β o in (6) gives the required coupling length, which is found to be 21 mm. The resultant dispersion curves are illustrated in Fig.…”

Section: Hybrids Pec/pmc Couplermentioning

confidence: 99%

See 1 more Smart Citation

Analytical Design Procedure for Forward Wave Couplers in RGW Technology Based on Hybrid PEC/PMC Waveguide Model

Beltayib

Sebak

2019

IEEE Access

View full text Add to dashboard Cite

In this paper, a systematic design methodology of a 0dB and a 3dB forward couplers based on the ridge gap waveguide (RGW) technology is presented. This methodology is based on exact theoretical formulations rather than any approximate or empirical equations. The procedure of the proposed design methodology is mainly to build a virtual equivalent waveguide model. This waveguide has two horizontal upper and lower perfect electric conductor (PEC) walls, while the left and the right walls are made of perfect magnetic conductors (PMC). A detailed analysis for this hybrid PEC/PMC waveguide, a common waveguide for coupling, is introduced as the starting phase for designing the RGW couplers. The equivalent RGW coupler that assures the same operation of the hybrid PEC/PMC waveguide at a specific frequency range is deduced based on detailed theoretical aspects. Moreover, a simple analyzing of transitional bends and phase shifters with accurate calculations is presented in this paper, which are the fundamental building blocks of several mmW components such as the six-port junction and the butler matrix. The possibility of tuning the coupler center frequency is introduced without the need of using any nonlinear elements. The resulting RGW couplers are implemented through well-known full wave simulator (Ansoft HFSS), with verification through prototype measurements in order to confirm the validity of the proposed methodology. A good agreement is achieved between measurement and simulation results. INDEX TERMS Hybrid forward couplers, periodic structure, ridge gap waveguide, hybrid PEC/PMC waveguide.

show abstract

Section: Hybrids Pec/pmc Couplermentioning

confidence: 99%

“…Many previous research efforts are conducted for implementing forward wave couplers based on different technologies. Some couplers are based on rectangular waveguides (RWG) [2], microstrip lines [3], substrate integrated waveguide (SIW) [4], nonradiative dielectric (NRD) waveguide [5], [6] and ridge gap waveguide (RGW) [7]- [9].…”

Section: Introductionmentioning

confidence: 99%

Analytical Design Procedure for Forward Wave Couplers in RGW Technology Based on Hybrid PEC/PMC Waveguide Model

Beltayib

Sebak

2019

IEEE Access

View full text Add to dashboard Cite

show abstract

“…In [4], a linearly polarized-circularly polarized conversion was achieved at sub-mm-wave frequencies by exploiting diff erential dispersion in hexagonal waveguides. In an orthomode transducer (OMT), a wideband circularly polarized wave can be generated by combining the two orthogonal linearly polarized signals into the waveguide structure [5][6][7][8][9][10][11][12][13][14][15]. This approach requires a dual input source and increased complexity, especially at millimeter-wave frequencies due to smaller feature sizes.…”

Section: Introductionmentioning

confidence: 99%

Analysis and design of a W-band circular polarized feed horn with built-in polarizer for low f/D offset-reflector antenna

Mishra

Sharma

Chieh

2020

URSI Radio Sci. Bull.

View full text Add to dashboard Cite

A novel low-axial-ratio W-band left-hand-circularlypolarized (LHCP) cylindrical waveguide feed horn antenna is described using a built-in polarizer. The built-in polarizer section of the horn consisted of nine pairs of circular cavities to generate circular polarization, eliminating the need for an external orthomode transducer or a complex septum. The polarizer was analyzed using the diff erential dispersion eff ect from the cavities along the length of the waveguide. The antenna had impedance matching ( 11 15 S   dB) and an axial ratio below 1.2 dB from 79.5 GHz to 88 GHz. The horn antenna was then used as a feed source to illuminate an off set parabolic refl ector of 10 cm diameter and a low 0.25 f D  . The feed-refl ector assembly was also integrated inside a 1U volume of a 6U-CubeSat chassis. The radiation performance was analyzed using the Multilevel Fast Multipole Method (MLFMM) along with the Method of Moments (MoM) in TICRA GRASP. The measurement of the prototyped feed horn and the off set parabolic refl ector antenna validated the analysis and simulation results.

show abstract

“…High gain with sufficiently large operating bandwidth, compact size and low losses are the essential requirements. Many previous research efforts are shown for realizing antennas and components work at MMW band based on different technologies (substrate integrated waveguide (SIW) [4], microstrip lines [5], non-radiative dielectric (NRD) waveguide [6], [7] and rectangular waveguide (RWG) [8], [9]).…”

Section: Introductionmentioning

confidence: 99%

$4\times4$ -Element Cavity Slot Antenna Differentially-Fed by Odd Mode Ridge Gap Waveguide

2019

View full text Add to dashboard Cite

A differential feeding for a cavity slot antenna is presented. The proposed feeding is based on a simple mechanism rather than the traditional complex networks that suffer from high losses. It is based on exciting the first higher order mode (TE 10) of the ridge gap waveguide (RGW) by enlarging the ridge width. This enlargement would excite some undesired even modes that are suppressed by inserting a vertical perfectly electric conducting (PEC) wall in the middle of the waveguide based on the concept of magic tee operation. The proposed 4 ×4 cavity slot antenna is implemented using substrate integrated waveguide (SIW) technology. Two horizontal slots on the top of proposed wide RGW, representing the differential feeding approach, are implemented to feed the cavity slot antenna. The slots couple the fields with same amplitudes and 180 • phase difference to the cavity. The electric fields of the two coupling slots have odd symmetry in the x-axis, and subsequently, uniform electric field distribution of the TE 440 mode of a cavity can be excited. The 4/4 radiating slots are etched on the top of the cavity in a specific distribution to ensure having in-phase fields for broadside radiation with low-cross-polarization levels. The measurement and simulation results of the proposed cavity slot antenna are in a good agreement. The obtained results confirm that the proposed antenna achieves a relative bandwidth of 7.1% for −10-dB return loss, a gain of about 16.5 dBi, and a side lobe level about −17 dB in E-plane and −13.8 dB in H-plane. Moreover, the proposed antenna provides low cross-polarization levels (−35 dB in E-plane and −27 dB in H-plane) within the operating frequency band of 32.5 to 34.9 GHz. With this achieved low profile, high gain, and high efficiency of the proposed cavity slot antenna, it may have a great potential for millimeter-wave (MMW) applications. INDEX TERMS Ridge gap waveguide, high order mode, differential feeding network, symmetric radiation, low cross polarization level, millimeter wave, back cavity antenna, substrate integrated waveguide.

show abstract

Design Methodologies of Compact Orthomode Transducers Based on Mechanism of Polarization Selectivity

Cited by 17 publications

References 31 publications

Analytical Design Procedure for Forward Wave Couplers in RGW Technology Based on Hybrid PEC/PMC Waveguide Model

Analytical Design Procedure for Forward Wave Couplers in RGW Technology Based on Hybrid PEC/PMC Waveguide Model

Analysis and design of a W-band circular polarized feed horn with built-in polarizer for low f/D offset-reflector antenna

$4\times4$ -Element Cavity Slot Antenna Differentially-Fed by Odd Mode Ridge Gap Waveguide

Contact Info

Product

Resources

About