Bit-Serial CMOS Digital IF-Filter for Mobile Radio using an On-Chip Clock

In English A chip for digital intermediate frequency filtering is introduced. The filter is intended move most of the analog intermediate frequency filtering to the digital domain in systems like the American mobile radio system (IS-54). It is a wave digital lattice filter realized with bit-serial arithmetic. Furthermore, a technique for local clocks on chip is presented. The method is based on a ring oscillator and a cycle counter which is controlled from outside the chip. A 0.8 micron technology custom test chip has been fabricated and tested.