Hardware Implementation of Mixed Signal Systems
Andrzej Handkiewicz · 2024
This chapter presents new perspectives in the design of filters based on multiport prototype gyrator–capacitor (gC) circuits. First, the design of a filter with corrected phase characteristics is presented. Since the transfer function of such a filter has zeros located in the right half-plane of the complex variables, it cannot be implemented using a prototype reciprocal circuit, such as the ladder reactance network. The nonreciprocal gC circuit is used for this purpose. This prototype circuit was implemented in the OTA-C technique, using the fully differential transconductance amplifiers. The use of one-dimensional (1D), multiport gC circuits to design filter banks is presented. The use of filter banks is demonstrated in an example of a frequency-interleaved (FI) analog-to-digital converter (ADC). The analysis filter bank of this converter is implemented as a switched-current (SI) circuit. However, the gC prototype circuit of the synthesis filter bank in the converter is implemented as a digital circuit.