Citation: Yang, S.; Hu, K.; Fu, H.; Ma,
K.; Lu, M. A 24-to-30 GHz
Ultra-High-Linearity
Down-Conversion Mixer for 5G
Applications Using a New
Linearization Method. Sensors 2022,
22, 3802. https://doi.org/
10.3390/s22103802
Academic Editor: Alexandros-
Apostolos Boulogeorgos
Received: 19 April 2022
Accepted: 16 May 2022
Published: 17 May 2022
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Article
A 24-to-30 GHz Ultra-High-Linearity Down-Conversion Mixer
for 5G Applications Using a New Linearization Method
Shenghui Yang
1
, Kejie Hu
1
, Haipeng Fu
1,
*, Kaixue Ma
1
and Min Lu
2
1
School of Microelectronics, Tianjin University, Tianjin 300072, China; yangshenghui@tju.edu.cn (S.Y.);
hkj@tju.edu.cn (K.H.); makaixue@tju.edu.cn (K.M.)
2
State Key Laboratory of Mobile Network and Mobile Multimedia Technology, ZTE Corporation,
Shenzhen 518000, China; lu.min1@zte.com.cn
* Correspondence: hpfu@tju.edu.cn
Abstract:
The linearity of active mixers is usually determined by the input transistors, and many
works have been proposed to improve it by modified input stages at the cost of a more complex
structure or more power consumption. A new linearization method of active mixers is proposed in
this paper; the input 1 dB compression point (IP1dB) and output 1 dB compression point (OP1dB) are
greatly improved by exploiting the “reverse uplift” phenomenon. Compared with other linearization
methods, the proposed one is simpler, more efficient, and sacrifices less conversion gain. Using this
method, an ultra-high-linearity double-balanced down-conversion mixer with wide IF bandwidth is
designed and fabricated in a 130 nm SiGe BiCMOS process. The proposed mixer includes a Gilbert-
cell, a pair of phase-adjusting inductors, and a Marchand-balun-based output network. Under a
1.6 V supply voltage, the measurement results show that the mixer exhibits an excellent IP1dB of
+7.2~+10.1 dBm
, an average OP1dB of +5.4 dBm, which is the state-of-the-art linearity performance
in mixers under a silicon-based process, whether active or passive. Moreover, a wide IF bandwidth of
8 GHz from 3 GHz to 11 GHz was achieved. The circuit consumes 19.8 mW and occupies 0.48 mm
2
,
including all pads. The use of the "reverse uplift" allows us to implement high-linearity circuits more
efficiently, which is helpful for the design of 5G high-speed communication transceivers.
Keywords: 5G; SiGe BiCMOS; linearization techniques; millimeter waves; mixers
1. Introduction
The fifth-generation (5G) wireless network is one of the most attractive research
hotspots in recent years. To obtain wider bandwidth and higher communication rates, the
frequency of 5G applications is increased gradually towards millimeter-wave bands. To
save the time to market as much as possible, the circuits should cover multiple frequency
bands to avoid repeated design when new applications appear, which brings greater design
challenges to improve performance at the same time. Some broadband receivers covering
multiple frequency bands have been proposed for 5G new radio (NR) frequency bands,
including 24.5, 28, 37, 39, and 43 GHz [1,2].
In the receiver of a heterodyne structure, the down-conversion mixer is located be-
tween LNA and VGA, in the second stage. Parameters such as conversion gain (CG),
1dB compression point, noise figure (NF), and isolation cannot be ignored and seriously
affect the system’s overall performance. Moreover, the data rate of several Gbps is highly
expected, which requires the mixer’s intermediate frequency (IF) to be higher and have a
wide IF bandwidth.
For passive mixers, resistive ring mixers [
3
] and drain-driven mixers [
4
] all have a
significant loss at millimeter-wave frequencies, which requires additional power consump-
tion to compensate, and higher local oscillator power requirements make the system more
complicated. Various active implementations have been proposed under silicon-based
Sensors 2022, 22, 3802. https://doi.org/10.3390/s22103802 https://www.mdpi.com/journal/sensors
