Shakila Bint Reyaz

Self-actuation tests of ohmic contact and capacitive RFMEMS switches for wideband RF power limiter circuits

This paper presents an experimental study on the high power handling capabilities of some ohmic contact based and capacitive RF-MEMS switches (incl. self-actuation tests made up to 18 GHz). Such tests carried out on a series and shunt connected ohmic contact COTS MEMS switch show that self-actuation occurred at 29-37 dBm of RF input power (Pin) given a DC bias (Vbias) of 42-47 V. Corresponding high power tests of a capacitive MEMS switch made on quartz (at 4 GHz) show that self-actuation occurred at Pin = 24-31 dBm with Vbias = 0-19 V. The experimental results further indicate a potential usefulness of employing ohmic contact and capacitive MEMS switches to realize optimised low-loss wideband power limiter circuits.

Design and test results of a wideband sige detector and on-chip slot antenna for W-band sensing applications

This paper presents the circuit designs and results of a wideband power detector and an on-chip slot antenna fabricated in a 0.25 μm SiGe BiCMOS process. The W-band SiGe detector has close to 20 GHz of operational bandwidth (s11≤-10 dB at 75-92 GHz) and a responsivity of 3-5kV/W (NEP = 10-16 pW/Hz1/2) at 83-94 GHz. The SiGe on-chip slot antenna design covers a wide bandwidth (70-110 GHz) with 2 dBi of simulated gain at 94 GHz. The realised wideband SiGe BiCMOS power detector and on-chip antenna are targeting highly integrated single-chip RF front-ends for broadband sensing applications up to 110GHz.

RF-MEMS reconfigurable GaAs MMICs and antennas for microwave/MM-wave applications

This paper presents the results of some reconfigurable RF-MEMS switching circuits and antennas fabricated using GaAs MMIC and LTCC based processes. Wafer-level packaged GaAs RF-MEMS series and shunt switches demonstrating low losses (≤ 0.5 dB) up to 40 GHz are presented together with a compact Ka-band GaAs MEMS 3-bit phase shifter circuit and LTCC based array antenna modules. Furthermore, some GaAs MMIC wideband/V-band RF-MEMS switching networks and a W-band on-chip slot antenna design show promising RF properties for broadband mm-wave applications related to wireless communication and RF-sensing.

A GaAs MMIC Single-Chip RF-MEMS Switched Tunable LNA

This paper presents a novel compact circuit design of an RF-MEMS frequency-agile LNA realized in a GaAs MMIC process that also includes a BCB cap type of wafer-level package. The uncapped/BCB capped single-chip GaAs MEMS tunable LNA circuits which can be matched at different frequency bands (e.g at X-band and Ku-/K-band) present similar in-band gain, linearity and noise figure over 30-60% wide tuning ranges (the uncapped MEMS tunable LNA has an NF≤3 dB at 14-21 GHz with ≤0.6 dB higher NF at 9-13 GHz). The validated MMIC designs are first time realizations of uncapped/0-level packaged MEMS tunable (wide-band/narrow-band) LNAs in a GaAs foundry process.

A K-Band RF-MEMS-Enabled Reconfigurable and Multifunctional Low-Noise Amplifier Hybrid Circuit

A K-Band RF-MEMS-Enabled Reconfigurable and Multifunctional Low-Noise Amplifier Hybrid Circuit

A fully encapsulated waveguide coupled passive imaging W-band radiometer module with RF frontend IC in a SiGe-BiCMOS technology

Heterodyne and direct detection radiometer receivers at 94 GHz have been realized in a 130 nm Si/SiGe BiCMOS process. They have been assembled into fully self-contained metal housings with a waveguide flange for the antenna connection. The receivers, which employ a SiGe LNA with below 4 dB noise figure, show overall responsivities of 620 μV/K and 380 μV/K respectively.