Page 53 - ITU Journal Future and evolving technologies – Volume 2 (2021), Issue 2

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

4.1 The block diagrams and reference data approach to designing high-order MMW multiplier
for simulation [29] is shown in Fig. 4. As it follows from the figure,
the circuit is divided into 2 stages based on optical
The block diagram of the MWE-assisted RF multiplier Mach-Zehnder modulators (MZM) pumped by the
under study based on a typical approach to designing same semiconductor laser source (SLS). The MZM1
high-order MMW multipliers [28] is shown in Fig. 3. of the first one operates in the maximum

Table 1 – Common reference data transmission bias (MATB) mode implementing 4x
multiplication of the input RF signal (4.25 to
Parameter Value
17 GHz). Its output intensity-modulated optical
Input frequency 4.25 GHz spectrum including optical carrier and a set of
Output frequency 102 GHz higher harmonics of the RF subcarrier is converted
Multiplication factor 24 by a photodetector (PD1) into an RF band,
Input power ≥5 dBm amplified by an electrical amplifier (EA), and the
Transmission gain ≥-5 dB component of 17 GHz is selected using an RF
bandpass filter (RF BPF). The output signal of the
As it follows from the figure, due to the fact that a RF BPF is fed to the input of the second MZM2 that
high-order coaxial frequency multiplier is operates in the minimum transmission bias (MITB)
practically impossible to implement in the mode implementing 6x multiplication (17 to 102
microwave range [28], the circuit is divided into 3 GHz). Its output intensity-modulated optical
stages of active multipliers by 2 (MP2-1, MP2-2, spectrum including a partly suppressed optical
and MP2-3), followed by a multiplier by 3 (MP3) in carrier and a set of higher harmonics of the RF
a coaxial-waveguide design. To eliminate the subcarrier is filtered by an optical Bragg grating
higher harmonics arising in the process of this notch filter (OBGF) suppressing an optical carrier
nonlinear operation, after each multiplication and the two nearest harmonics of the RF signal. The
stage the corresponding bandpass filters (BPF1, remainder is gained by an optical amplifier (OA),
BPF2, BPF3 and BPF4) are introduced. Reference converted by a photodetector (PD2) into an RF
data for simulating this RF multiplier are given in band, amplified by EA3, and filtered by a
Table. 2. The parameters of all devices are taken waveguide bandpass filter (WG-BPF). Reference
from the websites of the respective manufacturers. data for simulating this RF multiplier is given in
Table. 3. The parameters of all devices are taken
The block diagram of the MWP-assisted RF
multiplier under study based on a known MWP from the websites of the respective manufacturers.

Fig. 3 – Block diagram of the MWE-based frequency multiplier under study

Fig. 4 – Block diagram of the MWP-based frequency multiplier under study (Optical connections are painted in red, electrical
connections in black)

© International Telecommunication Union, 2021 39