Page 57 - ITU Journal Future and evolving technologies – Volume 2 (2021), Issue 2

ITU Journal on Future and Evolving Technologies, Volume 2 (2021), Issue 2

under study. The measurement results are shown The following outcomes can be drawn from these
in Fig. 10 (a) for an MWE approach and in Fig. 10 figures.
(b) for an MWP approach.
– The output spectra of both schemes under study
have a high-side mode suppression ratio.
Nevertheless, due to the higher linearity of the
characteristics of the used optoelectronic devices,
its minimum value for the MWP approach turned
out to be 13 dB higher (90 dB vs 77 dB) than for the
MWE approach.
– Measurement of the amplitude characteristics
showed that the input power level of the MWP-
based scheme according to the standard criterion,
which is a 1-dB deviation from linear, is almost
5 dB higher than that of the MWE-based scheme.
Consequently, its dynamic band is significantly
(a) For MWE model better.

5. CONCLUSION
To choose the optimal principle for designing B5G
NG-RAN’s radio unit circuitry using a microwave-
electronics (MWE) or microwave-photonics
(MWP) approach, in this paper we performed a
comparative simulation for a specific example of
developing such an obligatory RU’s node as a
reference oscillator with an output frequency of
more than 100 GHz, which was typically
implemented by means of a circuit that includes a
relatively low-frequency RF oscillator followed by
(b) For MWP model a high-order frequency multiplier. In particular, we
Fig. 10 – Simulated output spectra for the frequency proposed and described two alternative schemes
multiplier under study for implementing a frequency multiplier from 4.25

In addition, their amplitude characteristics were to 102 GHz using an MWE or MWP approach. The
investigated. The measurement results of output goal of the simulation was to select an optimal
power vs input power are shown in Fig. 11. design concept for developing a high-order RF
multiplier of NG-RAN’s reference oscillator using
the same input and output powers and operating
frequencies. For both cases, Cadence AWRDE
software with an additional introduction of the
previously proposed models of optoelectronic
devices was implemented. To ensure the practical
orientation of the simulation experiments, the
parameters of the included active and passive
schematic elements were selected based on the the
specifications of commercially available discrete
components.

As a result, a comparison of the investigated
variants showed the potential advantage of the
MWP approach from the point of view of the
Fig. 11 – Amplitude characteristics for the frequency simplicity of the scheme, since even at the current
multiplier under study
level of optoelectronic device production, the

© International Telecommunication Union, 2021 43