An RF front-end for digital mobile radio

The authors present a bipolar transceiver chipset for application in new-generation digital mobile radio equipment. A transmitter and a receiver circuit for the RF front-end are described which are both realized in the bipolar technology OXIS-3 with a minimum feature size of 1.5 μm and a transit frequency of about 7.5 GHz. The main features of the chip set are: simple switch over from one standard to another; simple and reduced RF-design for the customer; reduced peripheral components; no alignment necessary; reduced board design area; reduced power consumption; and high modulation phase stability versus temperature and product life. Test results demonstrate the high performance of both circuits. With these transceiver chips, available in SMD-packages, a very compact, size-reduced RF-front-end module can be developed by the customers for mobile radio and hand portables