|
Characterizing the Effects of Mutual Coupling on the Performance of a Miniaturized GPS Adaptive Antenna Array
April 2000
Basrur Rama Rao, The MITRE Corporation
Jonathan H. Williams, The MITRE Corporation
C. Daniel Boschen, The MITRE Corporation
Jeffry T. Ross, The MITRE Corporation
Eddie N. Rosario, The MITRE Corporation
Robert J. Davis, The MITRE Corporation
ABSTRACT
This paper describes the design of a compact, M-code capable, four
element GPS adaptive antenna arrays made from stacked patch microstrip
antenna elements. Possible applications for these antenna arrays are
in military airborne platforms where the space available for installing
antennas is very limited. To meet future GPS M code requirements, the
antenna elements were designed for a bandwidth of 24 MHz. The size of
the entire array assembly including the metal ground plane on which
it is mounted is 4.625"; the size of the array itself is even smaller—only 3.5" square. The array also has a low profile with a height
of just 1.2" including the radome cover. The size of the microstrip
antenna elements has been reduced in size to fit within this aperture
by using high dielectric constant substrate materials. The technical
challenges in the design was to reconcile conflicting requirements imposed
by the small antenna size and the wider 24 MHz bandwidth demanded by
the M-code. Each element in the array fed by a self-diplexing feed consisting
of coaxial probes connected to surface mount quadrature hybrids for
circular polarization. Satisfactory M—code performance of the
antenna array has been demonstrated by measuring the signal fidelity
of the correlation peak using an M-code transmitter, down-converter
and receiver built at MITRE. The results of mutual coupling measurements
on this circularly polarized array are described with their impact on
array design. The antenna patterns and other pertinent performance characteristics
of this array are being measured. These results will be described in
a future paper.
Additional Search Keywords
N/A
|
