How is power supplied to the most common type of MMIC?

To keep MMIC packages as small and simple as possible, most common MMICs are designed with only two to four pins, typically serving as RF input, RF output, and ground. Because there isn't a dedicated DC power supply pin (Vcc), power must be fed into the device through the existing RF connections. Operating bias is supplied by injecting DC voltage directly into the RF output lead. A resistor and/or an RF choke is used in this connection to allow the DC power to reach the chip while preventing the high-frequency RF output signal from leaking back into the DC power supply. You cannot just connect power 'directly to a Vcc lead' because standard MMICs purposefully lack one. Similarly, feeding it through the input lead is incorrect; the output pin is the industry-standard injection point for providing bias to these devices.