low-power multi-band injection-locked wireless receiver
abstract
the demand for low-power high-performance wireless receivers has dramatically in-
creased with the emerging deployment of wireless sensor networks (wsns). among the
demodulation schemes, non-coherent receivers consume less power in comparison with its
counterpart, e.g. the coherent receiver, attributed to its simple architecture and fewer com-
ponents. the injection-locking based envelope detection design, consisting of a low-noise
amplifier (lna), injection-locked oscillator, and an envelope detector, has drawn a lot more
attention in recent years for low-power non-coherent demodulation. however, the utilization
of the injection-locked oscillator, providing
flexibility and high performance, remains quite
challenging.
this thesis describes both the circuit level and mathematical model of injection-
locking, allowing for the implementation of a cmos receiver offering low-power, high per-
formance and the ability to support multiple radio frequency bands. by leveraging both
fundamental and superharmonic injection-locking, the receiver is capable of operating at
ve frequency bands, e.g., 433 mhz, 863 mhz, 915 mhz, 950 mhz, and 2.4 ghz, used for
wsn applications.
one of the challenges of making use of superharmonic injection-locking is the narrow
lock range that is insufficient for the oscillator to implement frequency-to-amplitude conver-
sion under the locked-in status while maintaining low-power performance. a mathematical
model developed in this work reveals the relationship between the lock range of superhar-
monic injection-locking and the third-order coefficient of the nonlinearity. an examination
of the injection transistor operating in the weak and strong inversion region leads to the
discovery of an optimal biasing point in the subthreshold region where the maximum lock range can be attained.