Creates a polyphase FIR filter.

Parameters:¶

branches: int¶

The number of polyphase branches \(B\).

taps: ArrayLike¶

The prototype filter feedforward coefficients \(h[n]\).

input: 'hold' | 'top-to-bottom' | 'bottom-to-top' = 'hold'¶

The input connection method.

• "hold": The input signal \(x[n]\) is passed to each polyphase partition (used in interpolation).

• "top-to-bottom": The input signal \(x[n]\) is commutated across the polyphase partitions from top to bottom.

• "bottom-to-top": The input signal \(x[n]\) is commutated across the polyphase partitions from bottom to top (used in decimation).

output: 'sum' | 'top-to-bottom' | 'bottom-to-top' | 'all' = 'sum'¶

The output connection method.

• "sum": The output of each polyphase partition is summed to produce the output signal \(y[n]\) (used in decimation).

• "top-to-bottom": The output of each polyphase partition is commutated from top to bottom (used in interpolation).

• "bottom-to-top": The output of each polyphase partition is commutated from bottom to top.

• "all": The outputs of each polyphase partition are used in parallel (used in channelization).

streaming: bool = False¶

Indicates whether to use streaming mode. In streaming mode, previous inputs are preserved between calls to __call__().