The design of a single frequency ice gauge using a microstrip patch antenna

Ice gauges that are both highly sensitive and highly reliable are needed by the aerospace sector. One form of ice gauges uses a RMPA (Rectangular Microstrip Patch Antenna) to meter ice thickness with the help of multiple frequencies. The scheme uses a variable frequency generator, an impedance bridge and a frequency controller. The sensor relies on the principle that the changes in ice thickness result in a change in antenna impedance and the antenna becomes resonant at a different frequency. The microprocessor controlled variable frequency generator then seeks out the new resonant point and the thickness corresponding to that point is read off. At the department of Engineering Technology efforts are underway to design a new system that is less expensive, less bulky and at least as reliable as the previously mentioned design. This paper will elaborate on this scheme. The design does away with the variable signal generator and the impedance bridge to decrease both the cost and the size of the system. The design uses a RMPA and a printed circuit feed and detection network. Simulations have been run to both prove the concept and to study the effect of different kinds of ice formations (patterns) on the S11 of the antenna. Comments will be made on how a high impedance surface might benefit this design