Broadband Antennas for the Double Quantum Well Terahertz Detector

This work is focused on realizing terahertz
detectors based on the idea of photon-assisted
tunneling (PAT) in the double electron layer
tunneling transistor (DELTT). The detector employs a
broadband antenna integrated lithographically with
the DELTT. The antenna should be broadband to take
full advantage of the electrically tunable
characteristic of the DELTT device. This work deals
with the analysis and design of broadband antennas
to efficiently couple THz radiation to the DELTT
device. Numerous bowtie and log-
periodic antenna structures have been designed and
simulated that have broadband impedance
characteristics. The electromagnetic simulator IE3D
is used to perform simulations. Measurements on
sample antennas were also performed to examine the
agreement between simulation and experimental
results. A key feature of this work is the
development of an equivalent circuit model for the
combined antenna and the DELTT device that could be
valid at THz frequencies. The development of such a
model is extremely important to match the antenna
impedance to the device impedance, which is key to
enhance the coupling efficiency.