2010 年，Anritsu 宣布已成功研发出可定位 PIM 故障的专利技术——PIM 定位™ (DTP)。DTP 可显示出天线系统中出现 PIM 故障的位置，以及天线到天线系统以外的外部 PIM 源的距离。在提升从现场 PIM 测试接收的信息质量方面，这一技术创造了不可思议的重大进步。但在定位天线系统外的外部 PIM 方面仍存在一个问题，即 DTP 可显示天线到所定位的 PIM 源的距离，但无法显示其角度。如果天线的波束宽度为 120，则 PIM 源可能位于沿 DTP 所测距离的 120 弧度上的任何位置。
PIM Hunter is a patent-pending technology that allows a test technician to pinpoint the location of external PIM beyond the antenna. By walking along the arc of the DTP distance from the antenna with PIM Hunter technicians can pinpoint the source of the PIM typically within a few centimeters.
The PIM hunting process begins with an Anritsu PIM Master MW82119B to inject two high-power test signals into the system under test. The test signals broadcast through the site antenna, exciting any PIM sources in the RF path. These PIM sources behave like CW transmitters radiating the IM3 frequency in all directions. With the PIM Hunter test probe connected to a spectrum analyzer in burst detect mode (Spectrum Master MS2720T or BTS Master MT8220T) or in custom setting (Spectrum Master MS2712E/MS2713E, Site Master S332E/S362E, or Cell Master MT8212E/MT8213E) and an appropriate bandpass filter installed, technicians can “hunt” for these IM3 signal sources along the arc of the distance provided by the DTP measurement of the PIM Master MW82119B. When the probe tip comes in close proximity to a PIM source, the PIM value increases by as much as 30 dB, indicating the precise location of the PIM source. The Identifying Sources of External PIM white paper, found in the Library tab, provides more detail on the external PIM hunting process.
