Equivalent Circuit of Normal Mode Helical Antennas Using Frequency-Independent Lumped Elements

An equivalent circuit consisting of eight frequency independent lumped elements is derived for center-driven normal mode helical antennas. The equivalent circuit is composed of two parts; a five-element circuit representing the wire antenna and a three-element circuit for the helical turns. Comparison of the calculated input impedance of the equivalent circuit with full-wave simulations demonstrates reasonable agreement over a broad frequency range that includes the first resonant frequency, where the antenna usually operates. Application of the equivalent circuit does not require an EM solver and it is readily implemented in circuit simulators.

[1]  Rahul Sarpeshkar,et al.  Feedback Analysis and Design of RF Power Links for Low-Power Bionic Systems , 2007, IEEE Transactions on Biomedical Circuits and Systems.

[2]  Wire antennas coated with magnetically and electrically lossy material , 1979 .

[3]  Songcheol Hong,et al.  Design of a VHF/UHF/L-Band Low-Power Active Antenna for Mobile Handsets , 2012, IEEE Antennas and Wireless Propagation Letters.

[4]  N. Michishita,et al.  High performance normal mode helical antennas for RFID tags , 2007, 2007 IEEE Antennas and Propagation Society International Symposium.

[5]  O. Gandhi,et al.  On modeling and personal dosimetry of cellular telephone helical antennas with the FDTD code , 1998 .

[6]  A.R. Djordjevic,et al.  Optimization of Helical antennas [Antenna Designer's Notebook] , 2006, IEEE Antennas and Propagation Magazine.

[7]  K.S. Nikita,et al.  Study of the coupling between human head and cellular phone helical antennas , 2004, IEEE Transactions on Electromagnetic Compatibility.

[8]  H. A. Wheeler.  Simple Inductance Formulas for Radio Coils , 1928, Proceedings of the Institute of Radio Engineers.

[9]  Takehiro Imura,et al.  Study on open and short end helical antennas with capacitor in series of wireless power transfer using magnetic resonant couplings , 2009, 2009 35th Annual Conference of IEEE Industrial Electronics.

[10]  Donglin Su,et al.  Equivalent Circuit With Frequency-Independent Lumped Elements for Coated Wire Antennas , 2012, IEEE Transactions on Antennas and Propagation.

[11]  J. Jackson,et al.  Field Theory of Traveling-Wave Tubes , 1948, Proceedings of the IRE.

[12]  Todd H. Hubing,et al.  A Simplified Model for Normal Mode Helical Antennas , 2010 .

[13]  P. Excell,et al.  The Complete Surface-Current Distribution in a Normal-Mode Helical Antenna , 2012, IEEE Antennas and Propagation Magazine.

[14]  Gordon L. Stuber,et al.  Optimization of Helical Antennas , 2006 .

[15]  H. A. Wheeler,et al.  A Helical Antenna for Circular Polarization , 1947, Proceedings of the IRE.

[16]  W. Park,et al.  Simplified Vector Potential and Circuit Equivalent Model for a Normal-Mode Helical Antenna , 2013, IEEE Antennas and Wireless Propagation Letters.