A. Gustafsson

On the Use of MEMS Phase Shifters in a Low-Cost Ka-band Multifunctional ESA on a Small UAV

We present a system concept for a Ka-band multi-functional electronically steerable antenna (ESA) on a small UAV that is based on using sub-arrays with low-loss RF MEMS phase shifters. Our analysis shows that low phase shifter losses are critical if the dissipated radar hardware DC power should fit within the given requirements. The results presented in this paper also indicate that adequate performance (in terms of 2 dB of average losses at 35 GHz) can be possible to achieve with a Ka- band 4-bits MEMS phase shifter design made on quartz.

RF MEMS and GaAs Based Reconfigurable RF Front-End Components for Wide-Band Multi-Functional Phased Arrays

We study possibilities of implementing flexible and programmable components for the RF front-ends of wideband multi-functional phased arrays using GaAs MMIC and RF MEMS technologies. The use of MEMS reconfigurable matching networks in tunable bandpass LNAs is proposed to achieve wider tuning ranges (e.g. 6.5-9.9 GHz is obtained according to simulations) and adequate performance of such LNAs. We further demonstrate the potential for monolithic integration with active devices by showing how variable MEMS capacitors may be realized in a GaAs foundry process

A K-band single-chip reconfigurable/multi-functional RF-MEMS switched dual-LNA MMIC

A K-band (18–26.5 GHz) single-chip reconfigurable and multi-functional RF-MEMS switched dual-LNA MMIC (optimized for lowest/highest possible noise figure/linearity) is presented. The two MEMS switched low-NF and high-linearity LNA circuit functions present 18.6 dB/9.0 dB, 2.4 dB/3.5 dB and 22 dBm/29 dBm of small-signal gain, noise figure and OIP3 at 20 GHz, respectively. The in-band isolation levels of the two switched LNA paths equal 16–20 dB when the MEMS switches are switched on and off. Compared with two fixed (non-reconfigurable) LNA breakout circuits, the MEMS switched LNA circuit functions show 0.5–1.0 dB higher NF together with similar values of linearity at 15–25 GHz.

Monolithic integration of millimeter-wave RF-MEMS switch circuits and LNAs using a GaAs MMIC foundry process technology

Wideband millimeter-wave RF-MEMS switch networks and active RF circuits have been monolithically integrated on the same GaAs wafer using an MMIC foundry process technology. GaAs MEMS SPST and SPDT switches present below 1 dB of insertion loss and more than 8 dB/20 dB of isolation up to 75 GHz and 40 GHz, respectively. A compact 1-bit Ka-band GaAs MEMS phase shifter circuit achieve a high figure-of-merit with respect to low in-band losses for a given phase shift. The demonstrated on-wafer integration of two wideband LNAs further show the capabilities of realizing highly integrated (single-chip) reconfigurable active RF-MEMS based MMICs and front-ends at millimeter-wave frequencies.

A 7.9-9.7 GHz on-chip radar receiver front-end for future adaptive X-band smart skin array antennas

In this paper, we present a 7.9-9.7 GHz on-chip radar receiver front-end intended for a digital beamforming X-band smart skin phased array antenna. This agile single-chip receiver front-end could potentially enable a significant size and cost reduction of the microwave receiver modules in such an adaptive frequency hopping radar system. Measured results show a close to adequate performance.

A fully integrated radar receiver front end including an active tunable band pass filter and an image rejection mixer

A fully integrated X-band radar receiver front end based on only one down converting stage has been designed. The two chip MMIC (monolithic microwave integrated circuit) front end includes an active tunable bandpass filter in combination with an image rejection mixer. A novel digital time shifter is utilised to accomplish the tunability of the bandpass filter. The tuning range of the filter is between 8.7 and 9.8 GHz. With the intermediate frequency (IF) equal to 360 MHz, the total image rejection of the front end exceeds 45 dB. These results indicates that a compact one chip X-band radar receiver front end can be achieved.

A tunable active MMIC filter for on-chip X-band radar receiver front-ends

A 7.9-9.7 GHz tunable active monolithic microwave integrated circuit (MMIC) filter intended future on-chip X-band radar receiver front-ends is presented together with measured and simulated results. Typical measured filter data over the agile frequency band show a maximum gain of 11-16 dB, a noise figure of 6 dB, an input-referred third order intercept point of 0 dBm and 20-23 dB of out-of-band rejection at 2 GHz below the filter center frequency.

Analysis of tunable narrow-band recursive active MMIC filters for future adaptive on-chip radar receivers

A novel frequency tunable X-band MMIC filter design based on a balanced cascaded second order recursive active filter topology is presented together with simulation results. The simulated results indicate that this filter design can achieve a performance adequate for future advanced on-chip radar receivers.

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.