The TBPF-430-890 from Fraunhofer is a Digitally Tuneable Bandpass Filter that operates from 480 to 890 MHz. It consists of three coupled resonators and a digitally tunable capacitor that allows the centre frequency to be tuned with a resolution of 5 bits. The filter has an insertion loss of less than 5.5 dB, an OIP3 of 39 dBm and provides an attenuation of more than 55 dB in the stopband. It has a switching speed of 12 μs and a start-up time of 100 μs. The filter covers frequency range including the UHF-band within its TV white spaces (TVWS) and the LTE-800 frequency band. It can handle an input power of up to 33 dBm and requires a supply voltage of 3.3 V.
The filter is available as a surface-mount solderable module that measures 14 x 15 mm with a 3-wire SPI interface. It is suitable for RF harmonic filtering applications such as multi-band receiver/transmitter, multi-standard transceiver, software defined radio (SDR), cognitive radio and frequency monitoring.