Amplitude balance vs Phase balance in power divider

This page mentions basic definitions of amplitude balanace and phase balance.It covers difference between amplitude and phase balance with respect to RF power divider.

Amplitude Balance

Amplitude Balance:
It is measured at output ports of RF power divider or RF hybrid coupler. It is basically maximum peak to peak amplitude difference at the ouput ports. It is measured in dB. The frequency range usually is specified for this specification.

Let us assume that power divider has two output ports and it is a 3dB power divider. Here amplitude balance is a measure of how evenly power is splitted between the two output ports of the device.

The amplitude balance is not applicable to RF directional coupler as they have uneven power ratio. Typically amplitude balance is less than 0.25 dB for 2 way power divider and 0.4 dB for Quad hybrid coupler. The Marki Microwave products meet these requirements.

Phase Balance

Phase Balance:
It is measured at output ports of RF power divider or coupler. It is basically maximum peak to peak phase difference at the ouput ports over desired frequency range. It is measured in degrees.

In other words, phase balance is a measure of differential phase shift between the two output ports. This is applicable to equal output power components of power divider or quadrature hybrids.

Typically it should be in few degrees. This phase balance will get worse at high frequencies.