Design and Analysis of SPDT Switch and Array Antenna for 28 GHz 5G New Radio

We report a low-insertion-loss (IL), high-isolation, and high-linearity CMOS SPDT switch and a
$4\times 4$
array antenna for 28 GHz 5G NR. The transmit (TX) path consisting of a parallel DTMOS transistor
$\mathrm{M}_{1}$
with a large R (DTMOS-R), a series
$\lambda/8$
transmission line (TL), and a parallel capacitance
$(\mathrm{C}_{\text{ant}})$
. The
$\lambda/8- \text{TL}$
in conjunction with the parallel
$\mathrm{C}_{\text{ant}}$
and parasitic capacitance of transistors
$\mathrm{M}_{1}/\mathrm{M}_{2}$
constitute an equivalent
$\lambda/4-\text{TL}$
with Zc of
$50 \Omega$
. This leads to low IL in TX mode and decent isolation in receive (RX) mode. The RX path is an L-network constituting a series impedance and a parallel DTMOS-R
$\mathrm{M}_{3}$
. This leads to high linearity in RX mode and decent isolation in TX mode. In TX mode, the SPDT switch achieves measured IL of 0.58-1 dB for 17-34.9 GHz, isolation of 25.6-62.3 dB for 17-34.9 GHz, and
$\mathrm{P}_{1\text{dB}}$
: of 28.5 dBm at 28 GHz. These are one of the best IL and isolation results ever reported for mm-wave SPDT switches. In RX mode, the SPDT switch achieves measured IL of 1.9 dB, and isolation of 25 dB. The
$4\times 4$
array antenna achieves minimum
$\mathrm{S}_{11}$
of −40.4 dB at 28.85 GHz and S11 smaller −10 dB for 28.5-31.1 GHz, and decent gain of 10.1 dB at 30 GHz.