الفهرس 
Title : A Fully integrated 30 GHz Phased Array Transmitter Front-End for Satellite Communication
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Abstract
This work presents a fully integrated transmitter (TX) front-end for fifth generation
(5G) satellite communication in the Ka-band around 30 GHz. The TX employs radio
frequency (RF) phase shifting for beamforming. Phase shifting is achieved through a
vector modulator which uses weighted combining of the in-phase and quadrature (I/Q)
components of the signal to obtain the required phase shift, I/Q components are generated
using a symmetric poly-phase filter (PPF) and weighted combining is implemented through
digital current steering variable-gain amplifiers (VGAs). The vector modulator is followed
by a two-stage pre-driver and a variable output power switching power amplifier (PA)
as a fully integrated TX front-end. The TX achieves a 360° phase shifting range with a
resolution of 1.4° (8-bit) and a maximum saturated watt level output power (Psat) of 31
dBm while achieving an overall efficiency of around 40%. The transmitter front-end is
implemented in 22 nm FDSOI technology with a 1.8 V supply.
Layout optimization techniques were used to achieve such high phase shifting resolution.
To the best of the author’s knowledge, this is one of the highest reported resolutions at
this frequency range. Additionally, the transformer-based power combining scheme known
as distributed active transformer (DAT) is used to obtain the required high output power
efficiently. The high TX efficiency is achieved through utilizing an inverse-D class power
amplifier as the building unit of the switching PA stage. A thin/thick cascode structure is
used to tolerate the 1.8 V supply as well as reliably distribute the high output swing of the
PA. Finally, a simple efficient power control technique is implemented where the cascode
bias voltage is varied to vary the switching resistance and accordingly control the output
power. The proposed TX front-end high phase resolution, output power, and efficiency
make it an excellent candidate for phased arrays used in 5G satellite communication in the
Ka-band around 30 GHz.