Matching Bandwidth Limits for Arrays Backed by a Conducting Ground Plane

Matching bandwidth limits are developed for antenna arrays backed by a perfect electrically conducting (PEC) ground plane. We model a general array in the long wavelength limit as a thin PEC-backed slab and use Fano's method to determine a limit for the frequency integral of the reflection coefficient. This yields a simple expression for the maximum bandwidth of the array under TE or TM excitation, subject to a specified tolerance for mismatch and efficiency. The limit also depends on the array's thickness, scan angle, and static permeability. The special case of a thin planar radiating sheet placed above a ground plane is also considered, which has a maximum impedance bandwidth of 8.3:1 at broadside when no materials are used $({\hbox{VSWR}}\leq {\hbox{2{:}1}})$. Previous empirical approximations for the minimum height of a wideband array and maximum bandwidth of a tightly coupled dipole array (TCDA) are compared with the theoretical limits and found to be in good agreement.

[1]  Jin-Liang Wan,et al.  Broadband matching of multi-port networks terminated in frequency-dependent loads , 1985 .

[2]  Mats Gustafsson,et al.  Physical Bounds and Sum Rules for High-Impedance Surfaces , 2011, IEEE Transactions on Antennas and Propagation.

[3]  John L. Volakis,et al.  Bandwidth limits for lossless planar arrays over ground plane , 2012 .

[4]  H.A. Wheeler,et al.  Fundamental Limitations of Small Antennas , 1947, Proceedings of the IRE.

[5]  James G. Maloney,et al.  Wide scan, integrated printed circuit board, fragmented aperture array antennas , 2011, 2011 IEEE International Symposium on Antennas and Propagation (APSURSI).

[6]  Ben A. Munk,et al.  Finite Antenna Arrays and FSS: Munk/Finite Antenna Arrays , 2005 .

[7]  B. Tomasic,et al.  Minimum Q of the element in an infinite phased array , 2007, 2007 IEEE Antennas and Propagation Society International Symposium.

[8]  P.I. Richards,et al.  Resistor-Transmission-Line Circuits , 1948, Proceedings of the IRE.

[9]  Wai-Kai Chen,et al.  Broad-band matching of multiport networks , 1984 .

[10]  B. Tomasic,et al.  Minimum Q of the element in an infinite phased array - TMz case , 2007, 2007 19th International Conference on Applied Electromagnetics and Communications.

[11]  J. L. Volakis,et al.  A 6.3∶1 bandwidth scanning Tightly Coupled Dipole Array with co-designed compact balun , 2012, Proceedings of the 2012 IEEE International Symposium on Antennas and Propagation.

[12]  J. L. Volakis,et al.  A Simple Equivalent Circuit Model for Ultrawideband Coupled Arrays , 2012, IEEE Antennas and Wireless Propagation Letters.

[13]  Andrea Neto,et al.  Green's Function Based Equivalent Circuits for Connected Arrays in Transmission and in Reception , 2011, IEEE Transactions on Antennas and Propagation.

[14]  D. Cavallo,et al.  Analytical Description and Design of Printed Dipole Arrays for Wideband Wide-Scan Applications , 2012, IEEE Transactions on Antennas and Propagation.

[15]  John L. Volakis,et al.  Interwoven Spiral Array (ISPA) With a 10:1 Bandwidth on a Ground Plane , 2011, IEEE Antennas and Wireless Propagation Letters.

[16]  J. J. Lee,et al.  Compact light weight UHF arrays using long slot apertures , 2006 .

[17]  L. J. Chu.  Physical Limitations of Omni‐Directional Antennas , 1948 .

[18]  Mark Jones,et al.  A New Approach to Broadband Array Design using Tightly Coupled Elements , 2007, MILCOM 2007 - IEEE Military Communications Conference.

[19]  A.R. Lopez,et al.  Review of narrowband impedance-matching limitations , 2004, IEEE Antennas and Propagation Magazine.

[20]  D. Sjöberg.  Low-frequency scattering by passive periodic structures for oblique incidence: low-pass case , 2009 .

[21]  R. Fano.  Theoretical limitations on the broadband matching of arbitrary impedances , 1950 .

[22]  Daniel H. Schaubert,et al.  Vivaldi Antenna Arrays for Wide Bandwidth and Electronic Scanning , 2007 .

[23]  M. Gustafsson.  Broadband Self-Complementary Antenna Arrays , 2007 .

[24]  Ben A. Munk,et al.  Broadband Wire Arrays , 2003 .

[25]  J. Kasemodel.  Low-profile ferrite loaded UWB tightly coupled dipole array , 2011, 2011 IEEE International Symposium on Antennas and Propagation (APSURSI).

[26]  W. Habicht,et al.  The advanced multifunction RF concept , 2005, IEEE Transactions on Microwave Theory and Techniques.

[27]  R. C. Hansen,et al.  Antennas with magneto‐dielectrics , 2000 .

[28]  K. Rozanov.  Ultimate thickness to bandwidth ratio of radar absorbers , 2000 .