A design technique for concurrent multiband tunable loads from 0.4–6GHz with independent Q tuning

摘要

This paper presents a preliminary attempt at designing a concurrent multiband tunable load. Each band is independently tunable and the centre frequency of each band can be placed anywhere from 400MHz to 6GHz. This is done through the use of high frequency impedance inverters which enable each band to be tuned independently. The design has been implemented in a low cost 0.25μm BiCMOS process using 1μm HBTs operating at 1.2mA from a +/-2.2V supply. The circuit is targeted at 5G wideband applications requiring narrow band filtering where the bandwidth also needs some degree of tunability. The results show that high Q factors of over 100 can be achieved and that the individual bands show independent tunability. Although the circuit is demonstrated for three bands it is easily extendible to a higher number of bands.