RF Test Equipment Series: RF Test Probes and Antennas

In addition to coaxial and waveguide interconnects, there are two other major devices that interact with the DUT in RF/microwave/millimeter wave testing. They include surface probes attached to component leads or microstrip pads, and antennas designed for testing. The types of tests for which test probes and antennas are suitable vary widely, but both are critical in the characterization, conformance, and quality testing of RF devices and components.

RF Test Probes

Test probes typically consist of a waveguide or coaxial connector that fits the probe pin pattern. Probe pin types include single pin, ground/signal pin, ground/signal/ground pin, and coaxial pin. These probes are suitable for connecting component/device test points or pin trays located on semiconductor wafers, chip surfaces, or printed circuit board (PCB) surfaces. If coaxial or waveguide connectors cannot be placed on the surface or component/device due to performance, cost, or space constraints, probes are often used in this case.

One of the most common uses of RF test probes is for wafer-level testing of components and devices operating at high frequencies. In some cases, some RF test probes are suitable for testing millimeter-wave circuits that operate up to hundreds of GHz. There are also several types of RF test probes that can be soldered or mechanically attached to a test surface (usually the surface of a PCB). However, they are only used when such high quality and costly interconnections are absolutely necessary, as they usually cannot be withdrawn without sacrificing the quality of the interconnect.

RF test probes are often used in conjunction with probing equipment that has a high-caliber positioning mechanism or electronics that allow for minor adjustments to the probe x, y, and z, as well as additional axes. Some simple mechanical test probe positioners are only capable of holding the probe in place during testing, while more sophisticated probe positioners with robotic capabilities can be programmed to automatically position the probe for high-volume testing.

RF Test Antennas

An RF test antenna can be used for over-the-air (OTA) testing. It is typically tested to communications standards and electromagnetic compatibility (EMC) standards. In these test cases, the device under test (DUT) is usually placed in an open air test range (OATR) with low electromagnetic interference or in a full-wave dark room built for this purpose. Typically, such antennas must conform to a precise performance description as defined by the standard. This includes precise gain, directivity, VSWR, and localization requirements.

However, OTA testing is also applicable in other situations. Applications include internal testing using radar and platform-mounted equipment (e.g., ground vehicles and aircraft) to confirm performance and operation during loading. Since the type of antenna used for this test depends on the system to be tested, we offer a wide range of antenna types for you to choose from. Antenna types include conical/horn waveguide, broadband waveguide, omnidirectional waveguide/coaxial, Yagi coaxial, and other antenna types.