RF modules comprise of a combination of devices to perform a specific function in an RF system. They do not fit into the standard RF module categories and may be a combination of several functions. They may operate in uncommon frequency bands or system applications. A unique example of the radar systems is the pulsed power module. This is a collection of power transistors that when combined with other modules can create high power transmitters. They are usually specified as having a very high output power over a low duty cycle with a specified pulse rate. They typically are available as a flanged module for attachment to a heat sink and are specified to operate over a high-frequency range. Another unique device in this category is the analog phase shifter module. They are available to operate over a wide frequency range, for example 6-18GHz. The control portion is specified to operate over a particular modulation frequency bandwidth with a maximum phase change specified, which allows a carrier to be directly phase modulated if required. They are utilized in fiber optic and military applications. There are many other RF modules that may fall into a miscellaneous category. Many of them are ultra-high frequency devices utilized in applications including military, fiber communications, industrial, medical and test and measurement equipment.