Transmission line model for analysis of microstrip travelling wave antennas with right angled bends

Abstract A simple but accurate transmission line model for the analysis of microstrip travelling wave antennas based on microstrip lines and right angle bends is described. Radiated far fields from the antenna are calculated using magnetic current on the antenna sidewalls and electric current on the strip surface. Local reflections from the right angle discontinuity are considered in internal field calculations. An equivalent decay constant to accommodate the radiated power from the antenna is introduced which is iteratively computed to improve impedance and radiation characteristics calculated by the model. Total power lost in the line due to this equivalent decay constant is equal to the total power radiated from the antenna. A rampart line antenna having three unit cells is fabricated in the C band and the results from the model are compared with those from full wave MoM simulations and practical measurement with good agreement. This simple yet accurate model would be valuable in computer aided design for optimal microstrip line based antennas with minimal computational resources.

[1]  Majid Ahmadi,et al.  A novel phase coding method in chipless RFID systems , 2015 .

[2]  Gunter Kompa,et al.  Planar waveguide model for calculating microstrip components , 1975 .

[3]  N. Kikuma,et al.  Low-Sidelobe Design of Microstrip Comb-Line Antennas Using Stub-Integrated Radiating Elements in the Millimeter-Wave Band , 2012, IEEE Transactions on Antennas and Propagation.

[4]  J. Yamauchi,et al.  Analysis and measurements for improved crank-line antennas , 1997 .

[5]  Alice Buffi,et al.  Multifunctional modular antenna for near-field ultra-high frequency radio frequency identification readers , 2016 .

[6]  L. Lewin,et al.  Radiation from discontinuities in strip-line , 1960 .

[7]  Eric Rogard,et al.  Comparison of Radiation Modeling Techniques Up to 10 GHz—Application on a Microstrip PCB Trace , 2010, IEEE Transactions on Electromagnetic Compatibility.

[8]  C. Balanis.  Advanced Engineering Electromagnetics , 1989 .

[9]  C. Wood,et al.  Curved microstrip lines as compact wideband circularly polarised antennas , 1979 .

[10]  M. Leone,et al.  Closed-Form Expressions for the Electromagnetic Radiation of Microstrip Signal Traces , 2007, IEEE Transactions on Electromagnetic Compatibility.

[11]  Y. Kami,et al.  Analysis of radiation characteristics of a finite-length transmission line using a circuit-concept approach , 1988 .

[12]  Raj Mittra,et al.  Estimation of spurious radiation from microstrip etches using closed-form Green's functions , 1992 .

[13]  F Fernandes,et al.  Design, Development, and Fabrication of a Traveling-Wave Antenna on a Conical Surface , 2010, IEEE Antennas and Propagation Magazine.

[14]  H. Nakano,et al.  A Comb-Line Antenna Modified for Wideband Circular Polarization , 2015, IEEE Antennas and Wireless Propagation Letters.

[15]  Elson J. Silva,et al.  Design of the compact UHF RFID meander-line antenna loaded with CPW elements , 2017 .

[16]  Christos Christopoulos,et al.  Fast Prediction of Transmission Line Radiated Emissions Using the Hertzian Dipole Method and Line-End Discontinuity Models , 2014, IEEE Transactions on Electromagnetic Compatibility.

[17]  L. Shafai,et al.  Investigations on miniaturized endfire vertically polarized quasi-fractal log-periodic zigzag antenna , 2004, IEEE Transactions on Antennas and Propagation.

[18]  Teresa M. Martin-Guerrero,et al.  Electronically Steerable and Fixed-Beam Frequency-Tunable Planar Traveling-Wave Antenna , 2016, IEEE Transactions on Antennas and Propagation.

[19]  L. Shafai,et al.  Circularly polarised travelling-wave printed line antennas , 1989 .

[20]  A. Rydberg,et al.  Electrically Steerable Single-Layer Microstrip Traveling Wave Antenna With Varactor Diode Based Phase Shifters , 2007, IEEE Transactions on Antennas and Propagation.

[21]  Yan Wang,et al.  Broadband UHF RFID tag antenna with quasi-isotropic radiation performance , 2011 .

[22]  Ernesto Limiti,et al.  Traveling-wave antenna based on metamaterial transmission line structure for use in multiple wireless communication applications , 2016 .

[23]  Syarfa Zahirah Sapuan,et al.  Analytical Solution for Maximum Differential-Mode Radiated Emissions of Microstrip Trace , 2016, IEEE Transactions on Electromagnetic Compatibility.