Patent ID: 11923830
Assignee: HUAWEI TECHNOLOGIES CO., LTD.
Field: Telecommunications (Electrical engineering)
Classification: CPC H | IPC H

Claim 0:
1. An apparatus, comprising:
an input port;
an output port;
a tunable bandpass filter having a broad pass band connected between the input port and the output port the tunable bandpass filter configured to provide out-of-band rejection about a tunable frequency center having a wide tuning range;
a plurality of fixed frequency notch resonator filters each of a different corresponding fixed frequency center connected in parallel between a ground and a line connecting the tunable bandpass filter to the input port and/or the output port and configured to provide high rejection at the corresponding fixed frequency center, the fixed frequency centers configured such that when the frequency center of the tunable bandpass filter is between the frequency centers of a pair of the plurality of fixed frequency notch resonator filters having adjacent frequency centers, the frequency center of the pair of the plurality of fixed frequency notch resonator filters will be within the pass band of the tunable bandpass filter;
a plurality of switches whereby each of a corresponding one of the plurality of fixed frequency filters are selectively connectable to the line connecting the tunable bandpass filter to the input port and/or the output port by a corresponding one of the switches; and
a control circuit connected to the tunable bandpass filter and the switches and configured to:
tune the frequency center of the tunable bandpass filter to be between the corresponding frequency centers of a first pair of the plurality of fixed frequency notch resonator filters having adjacent frequency centers; and
with the frequency center of the tunable bandpass filter tuned to be between the corresponding frequency centers of the first pair of the fixed frequency notch resonator filters, selectively turn on the switches corresponding to the first pair of the fixed frequency notch resonator filters.