Algorithm for Calculating the Digital Radiophotonic Receiving Chain

Designing radio receiving paths for radio signals within the range of units-hundreds of gigahertz requires taking into account the noise properties and features of the corresponding element base, including the ADC. Electronic and photonic ADCs can be used in such systems. The aim of the work is to develop an algorithm for calculating a receiver with a microwave photonic ADC based on existing approaches to the design of receiving devices. It is shown that the method of calculating the noise factor of an ADC can be uniform for electronic and photonic ADCs. A step-by-step algorithm for calculating the parameters of the microwave photonic path based on the specified receiver technical characteristics and ADC is proposed. Calculation examples for radio monitoring systems requiring a large dynamic range and a wide Nyquist band while operating in several frequency bands, as well as a sufficient effective number of bits (ENOB), are considered. It is shown that in the computational examples for microwave photonic ADCs, significantly lower noise factor values can be achieved compared to the values typical for electronic ADCs. For the frequency range of 1-20 GHz, the estimated values of the noise factor of the microwave photonic ADC are at the level of 25.58-27.8 dB. This result is due to the use of a microwave photonic element base, which reduces the effect of set noise characteristic of electronic ADCs. The bandpass and anti-aliasing filters are calculated and the problem of their optimization is considered. An iterative approach to finding a compromise between the requirement for high sensitivity (low NF) and a large dynamic range (high PIP3) is presented by selecting parameters, constraints, and assumptions in the calculation algorithm.