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Improving
Return Loss of Bi-Conical Antennas By Mohammed A. Quddus
Abstract:
A method for improving return loss of a bi-conical antenna has been
investigated using FEKO simulation. Simulated results for the conventional
and modified bi-conical antennas are plotted as: (1) Return Loss vs.
Frequency, and (2) Directivity vs. Theta. A 3.5dB improvement in return
loss for the band, (0.5 - 2.0) GHz, is predicted for the modified bi-conical
antenna over the conventional bi-conical antenna. A comparison of simulated
results for the two cases indicates a small reduction in directivity due to
the modification, by 0.01dB at the low end and 0.75dB at the high end of the
band.
MEC's experience in airborne rigid and
flexible waveguides and passive components extends to virtually every
military aircraft including the following: A-3, A-4, A-6, A-7, AV-8,
B-1, B-2, B-52, C-130/AC-130U, E-2C, E-3A, EA-6B, E-8, EF-111, F-4,
RF-4B, F-8, F-14, F-15, F-16, F/A-18C/D, F/A-18E/F, F-27, F-104, KC-135,
P-2J, P-3C, RA-5C, SR-71, U-2, UH-60, Air Force One, FSX, Patriot,
PAC-3, Space Shuttle and Tornado
MEC has a unique expertise in
multi-frequency horns, multiplexers and millimeter wave components and High-Q
filters for radiometry and weather satellites for NASA, JPL, Aerojet, Ball
Aerospace, TRW and Hughes. Missile work includes: AMRAAM, COMPASS TIE, Condor,
ERINT, Firebrand, Hawk, Improved Hawk, Patriot and TOW
MEC has over 15 years experience in the
design, fabrication, and test of microwave and millimeter-wave antennas,
feeds, and components for space-based applications. In addition to our
internal capabilities in material selection, fabrication, and RF testing, MEC
has developed long term relationships with environmental test laboratories to
provide vibration, thermal cycling, thermal/vacuum, and launch environment
testing of MEC's hardware.
Some of our most recent projects include
Customer:
JPL/NASA
Program: NMP DS-J (Deep Space Comet
Rendezvous)
Description: MEC delivered two high-gain, dual circularly polarized Ka-band
corrugated horn antennas; all RF tests were performed by MEC.
Customer:
Aerojet/NASA
Program: EQS/A MS U-A (Space-based Radiometer)
Description: MEC is currently providing millimeter-wave
hardware including hybrid tees, diplexer/feedhorn assemblies and 4-frequency
multiplexer/feedhorn assemblies. MEC is responsible for environmental as well as RF
testing. MEC’s Q/A Plan for this program is in compliance with NASA Handbook NHB
5300.4 (1B).
Customer:
JPL/NASA
Program: Jason (Space-based Radiometer)
Description: MEC is currently providing two
three-frequency (one dual-polarized) corrugated feedhorns. MEC has performed all RF
testing including pattern testing of 1.2 meter offset reflector.
In addition to these recent projects, note that MEG has provided
space-qualified hybrids, multifrequency horns, multiplexers, High-Q filters and other
millimeter-wave components for NASA, JPL, Aerojet, Ball Aerospace, TRW, and Hughes in
support of programs such as
NIMBUS, TIROS, SMMR, and SSMIS.
In shipboard installations, MEC's
repertoire includes: AEGIS, LCAC, MK-86, MK-92, NATO Sea Sparrow, Phalanx,
SLQ-32, SPG-55, Types 8 & 15 periscopes and WLR-1.
On land, MEC supplies high power
combiners and dividers for Air Route Surveillance Radar (ARSR4) to
Northrop-Grumman, and Tri-Band Earth stations to L3, Comsat, Harris,
Motorola, AT&T. and CPI (Varian).
MAJOR CUSTOMERS
MEC has worked with the major prime contractors in the field, among them in
the United States: AT & T, Boeing, GEC-Marconi, GTE, Honeywell, Hughes, IBM,
ITT, Intel, Lockheed Martin, L3, LTV, McDonnell-Douglas, Raytheon, RCA,
Rockwell, Texas Instruments, Northrop-Grumman and many others. On the
international market, we supply Alcatel, BAE, Dassault, Decca, EEV, Elettronica,
Ericsson, Fokker, Fujitsu, Hawker-Siddeley, Inisel, Mitsubishi, Plessey, Saab,
THALES and Thorn.
From its inception as a supplier of
many unique and innovative products, MEC's greatest asset has been a closely
knit team of creative engineers, machinists and technicians who are
accomplished craftsmen in their trade. Our structure encourages teamwork and
has always been based on principles of TQM even before it became
fashionable. Our highly responsive management sustains complex programs from
design and prototype stages through full qualification, production and
subsequent upgrades. MEC has exhibited continuous growth despite a highly
competitive environment. This sustained growth is a direct result of the
loyalty of our customers and the recognition, which we have earned through
our support and teaming relationships.
MEC is classified as a small business;
our CAGE code is 06351.
FACILITIES
MEC is a vertically integrated and
quasi-self sufficient where all key processes are performed in-house giving
maximum control over the design and fabrication of the end product. Central
to our capabilities is an expert shop with CNC multi-axis machines and
lathes, abrasive machining, diamond grinding and tool making. Our
fabrication facilities include dip-brazing, welding, waveguide bending,
winding, heat treating, chemical treatment, rubber molding and painting. Our
testing laboratories include powerful RF vector and scalar systems up to 100
GHz, antenna ranges, high power transmitters, environmental chambers for
temperature, altitude, salt fog and humidity. Extensive software and
analytical tools are used throughout for CAD, CAM, CAE, synthesis, analysis
and simulation to design, produce and optimize our products.
All of MEC's products are passive
microwave devices and can easily be customized for specific frequency,
power, configuration and environment. The categories itemized below are only
meant to suggest common uses of our interwoven product lines. We welcome
your inquiries and look forward to working together with you.
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