The quadrature modulators and demodulators are widely used to create modern wireless communication systems. It is important to ensure high quality of the transmitted signals in order to have the exchange of information without loss or failure. From the point of view of the spectral decomposition of the signal (Fourier series decomposition), the useful component of the spectrum must be much larger than all other components. The carrier (LO frequency and spurious sideband are the most critical and undesirable quadrature modulator output signal spectral components. In the work, in the course of the research using the methods of suppressing the parasitic components, based on minimizing phase, amplitude and current imbalances in various nodes of the quadrature modulator circuit, have been revealed. In order to realize suppression, the special digital-to-analog converters are used in conjunction with a polyphase filter on varicaps, a phase-shifting block and current sources. The effectiveness of these methods is confirmed by the achievement of suppression of parasitic components in prototypes of 50 dB or more. It has been stated that the phase unbalance minimization is more effective than the amplitude unbalance minimization to sideband suppression. It has been revealed that the use of a phase-shifting block is a more suitable architecture to control the phase unbalance. The obtained results can be useful in the design of high-precision radio frequency units for various purposes.
Vladimir V. Losev
National Research University of Electronic Technology, Moscow, Russia
Yury A. Chaplygin
National Research University of Electronic Technology, Moscow, Russia
1. Pun K.-P., Franca J.E., Azeredo-Leme C. Circuit design for wireless communications. Improved techniques for image rejection in wideband quadrature receivers. Boston; Dordrecht; London: Kluwer Academic Publishers, 2003. 207 p.
2. The development of quadrature modulators and demodulators 1800 Mhz–6 Ghz with digital correction of parameters / R.S. Shabardin, N.V. Shabardina, I.I. Mukhin et al. // 2019 IEEE Conference of Russian Young Researchers in Electrical and Electronic Engineering (EIConRus). IEEE, 2019. P. 1612–1615.
3. A D-band 48-Gbit/s 64-QAM/QPSK direct-conversion I/Q transceiver chipset / S. Car-penter, D. Nopchinda, M. Abbasi et al. // IEEE Transactions on Microwave Theory and Tech-niques. 2016. Vol. 64. No. 4. P. 1285–1296.
4. Carpenter S., He Z.S., Zirath H. Multi-functional D-band I/Q modulator/demodulator MMICs in SiGe BiCMOS technology //International Journal of Microwave and Wireless Tech-nologies. 2018. Vol. 10. No. 5–6. P. 596–604.
5. Zhang Y. Wireless transmitter IQ balance and sideband suppression // Analog Devices, AN-1100 Application Note. 2010. P. 1–8.
6. Carpenter S., Abbasi M., Zirath H. Fully integrated D-band direct carrier quadrature (I/Q) modulator and demodulator circuits in InP DHBT technology // IEEE Transactions on Mi-crowave Theory and Techniques. 2015. Vol. 63. No. 5. P. 1666–1675.
7. Sanderson D.I., Svitek R.M., Raman S. A 5-6-GHz polyphase filter with tunable I/Q phase balance // IEEE microwave and wireless components letters. 2004. Vol. 14. No. 7. P. 364–366.
8. Шевцов И.В., Арьков А.В., Плехова М.А. Исследование и проектирование регули-руемого полифазного фильтра // Аллея науки. 2017. Т. 1. №. 15. С. 364–371.
9. The design of large image rejection and wideband CMOS active polyphase filter for Bei-Dou RF receiver / Y. Yin, Y. Ma, S. Kang et al. // IEICE Electronics Express. 2020. Vol. 17. No. 12. P. 1–5.
10. Leifso C., Nisbet J. A monolithic 6 GHz quadrature frequency doubler with adjustable phase offset // IEEE Journal of Solid-State Circuits. 2006. Vol. 41. No. 2. P. 405–412.
11. Недашковский Л.В., Тимошенков В.П., Шабардин Р.С. Сравнение способов ре-гулировки фазового разбаланса тракта гетеродина в квадратурных модуляторах и демоду-ляторах // Научно-практическая конференция «Интеллектуальные системы и микросис-темная техника»: сб. тр. М.: МИЭТ, 2020. С. 143–149.