Progress

Progress as of March 3, 2014

-Chose Wireline (F Antenna) approach.  It is simpler to design and to make smaller.

-Use quadrature network to couple two F antennas to create a left-hand circularly polarized (LHCP) signal.

-Geoforce currently uses an Antenova F antenna for the GPS signal (1575 MHz). By adjusting the length of the copper, we can achieve a higher frequency (1614 MHz).

Quadrature network

-Turns an input signal into two signals that are 90º out-of-phase with equal power.

-Includes a 50 ohm resistor in order to terminate reflections.

Progress as of April 20, 2014  

-Showed that it is possible to tune an Antenova A10204 GPS antenna from 1575MHz to the desired frequency of 1614MHz.
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-Repeated earlier procedure in order to prove that the antenna will resonate at the desired frequency with little to no major modifications.





Antenna Patterns (Azimuth)


Antenna Patterns (Elevation)


Design
- two linear antennas mounted perpendicularly driven by a quadrature hybried coupler.
- Mounting perpendicularly forces the electric fields to be perpendicaular to each other.
- Driving them with the hybrid coupler forces the signals to be 90 degrees out of the phase.
- The combination of the perpendicular electric fields and the 90 degrees difference creates a circularly polarized signal.

Manufacturing and Testing
- Manufacturing
  * Soldering antennas and hybrid coupler to the boards.
  * Board to be designed in the second semester, based on antenna performance and how they interact with the boards.
- Testing
  * Using network analyzer and antenna  chamber in communications lab, the follwing will be tested:
    - Gain
    - Antenna Pattern
    - VSWR

                      Schedule and Feasibility