The present disclosure relates to a radio system comprising an antenna device, an antenna connector arrangement and a radio transceiver with a transmitter branch and a receiver branch. The antenna connector arrangement connects the antenna device to the transmitter branch and to the receiver branch, and comprises a first tuneable band-stop filter, a second tuneable band-stop filter and a three-way-junction. The first tuneable band-stop filter is connected to the transmitter branch and a transmitter input port of the three-way-junction to filter radio signals, and the second tuneable band-stop filter is connected to the receiver branch and a receiver output port of the three-way-junction to filter radio signals. The three-way-junction comprises a first antenna port that is connected to the antenna device. The present disclosure also relates to an antenna connector arrangement, an antenna arrangement, and an electrically tuneable waveguide band-stop filter arrangement.

A waveguide with a curved-wall low-pass filter is described herein. The waveguide comprises a low-pass filter portion configured to allow low-frequency electromagnetic energy therethrough and reject high-frequency electromagnetic energy. The low-pass filter portion comprises an input port, an output port, and a cavity feature that is formed between the input port and the output port. The cavity feature has a greater depth than respective depths of the input port and the output port. The cavity feature comprises a bottom wall that achieves the greater depth for the cavity feature. The bottom wall comprises at least one curved portion configured to allow the cavity feature to achieve the allowance of the low-frequency electromagnetic energy and the rejection of the high-frequency electromagnetic energy. The cavity feature may allow the waveguide to have as good or better performance than traditional means while being easier to manufacture and/or taking up less space.

A waveguide with a curved-wall low-pass filter is described herein. The waveguide comprises a low-pass filter portion configured to allow low-frequency electromagnetic energy therethrough and reject high-frequency electromagnetic energy. The low-pass filter portion comprises an input port, an output port, and a cavity feature that is formed between the input port and the output port. The cavity feature has a greater depth than respective depths of the input port and the output port. The cavity feature comprises a bottom wall that achieves the greater depth for the cavity feature. The bottom wall comprises at least one curved portion configured to allow the cavity feature to achieve the allowance of the low-frequency electromagnetic energy and the rejection of the high-frequency electromagnetic energy. The cavity feature may allow the waveguide to have as good or better performance than traditional means while being easier to manufacture and/or taking up less space.