RF High Power BroadBand Power Amplifiers 90 Degree Hybrid Couplers

The 90 degree hybrid couplers is a special form of bidirectional coupler that has the following purposes:
1. Phase shifter: A 90 degree hybrid couplers is often used as a phase shifter, which can divide an input signal into two channels, one of which has the same phase as the original signal and the other is 90 degrees different (i.e. orthogonal) from the original signal, thus achieving phase shifting function.
2. Microwave mixer: The 90 degree hybrid couplers can also be used as a part of the microwave frequency mixer. In a mixer, the function of a 90 degree hybrid couplers is to add the RF signal to the signal generated by the local oscillator (LO), thereby generating up and down conversion signals.
3. Two way power divider: Since the 90 degree hybrid couplers can divide the input signal into two ways, it can be used as a two way power divider to ensure that the allocated signal has orthogonal phase difference when equal power is allocated.
4. For radio testing and measurement: The 90 degree hybrid couplers can be used to test the working condition of radio equipment. As it can divide the input signal into two channels, one of them can be used as a reference signal for calibrating the measurement equipment.