A Near Field Focused Microstrip Array for a Radiometric Temperature Sensor

A low-cost radiometric temperature sensor system is described, with emphasis on the use of a 12.5 GHz near-field focused microstrip array to provide a low-profile compact product suitable for commercial and industrial applications. An overview of the temperature sensor system is given, followed by design details of the focused microstrip array, including near-field patterns and antenna efficiency measurements. Temperature measurements made with the radiometric system in a food-processing plant field test show that the antenna can resolve individual hamburger patties at a practical measurement distance.