Jan Svedin

Single-Chip 220-GHz Active Heterodyne Receiver and Transmitter MMICs With On-Chip Integrated Antenna

This paper presents the design and characterization of single-chip 220-GHz heterodyne receiver (RX) and transmitter (TX) monolithic microwave integrated circuits (MMICs) with integrated antennas fabricated in 0.1- μm GaAs metamorphic high electron-mobility transistor technology. The MMIC receiver consists of a modified square-slot antenna, a three-stage low-noise amplifier, and a sub-harmonically pumped resistive mixer with on-chip local oscillator frequency multiplication chain. The transmitter chip is the dual of the receiver chip by inverting the direction of the RF amplifier. The chips are mounted on 5-mm silicon lenses in order to interface the antenna to the free space and are packaged into two separate modules.

A Micromachined 94 GHz Dielectric Resonator Antenna for Focal Plane Array Applications

In this paper a new concept of integrating micromachined high-resistivity (HR) silicon dielectric resonator antennas (DRAs) compatible with a millimeter wave multichip module deposited (MCM-D) process based on multiple layers of benzocyclobuthene (BCB) is presented. The HR Si wafer is used not only as a carrier substrate for the BCB but also for manufacturing of the integrated antenna elements. A 4times8 focal plane array (FPA) was designed for use in a 94 GHz imaging radar system. Each channel uses a small 2times2 DRA subarray as feed element. By using the presented antenna a higher impedance bandwidth and radiation efficiency can be attained compared to the use of microstrip antennas. An improved isolation between the antennas and the feed lines/active circuits is also realized.

A 60 GHz image rejection filter manufactured using a high resolution LTCC screen printing process

An LTCC test panel including various mm-wave test circuits has been designed and manufactured using a recently developed screen printing process (Thales Microelectronics) having a highly optimised resolution, here evaluated using a minimum microstrip line width/gap of 2 mil (50.8 ¿m). In this paper we report on a 60 GHz microstrip coupled lines bandpass filter manufactured on a 3.7 mil (94.0 ¿m) thick Ferro A6S substrate using a minimum line gap of 2 mil. The electromagnetic effects caused by the top conductor recess were taken into account using direct full-wave simulations (Ansoft HFSS) but also by a circuit simulation methodology based on the use of effective relative permittivity and substrate height parameters [1]. Preliminary measurement results show a 3 dB bandwidth of approximately 5 GHz, a passband insertion loss of 4 dB and a center frequency slightly above the simulated value. This bandpass filter could e.g. serve as an image rejection filter together with the 60 GHz WLAN chipset [2] where it would demonstrate a 55 GHz image suppression of approximately 20 dB.

A modified finite-element method for dielectric waveguides using an asymptotically correct approximation on infinite elements

A modified finite-element method for the propagation analysis of such dielectric waveguides as optical fibers and integrated optical waveguides is presented. Possible applications include nondissipative structures of arbitrary anisotropic media with, in some cases, inhomogeneous exterior regions. The method is based on the full vectorial finite-element formulation, which is known to be without spurious solutions. With this formulation all appropriate boundary and interelement conditions on both tangential and normal components are a priori satisfied. For the unbounded, exterior region a novel type of asymptotically correct approximation on infinite elements is proposed that simultaneously, for each mode and frequency, locally adapts the rate of radial decay to the transversal wavenumbers. The linearity of the original finite-element method has been retained by using beta /k/sub 0/ as a parameter, which results in a sparse generalized eigenvalue problem. Numerical examples including both optical fibers and integrated optical waveguides, isotropic as well as anisotropic, have been analyzed to confirm the validity of the method. The observed correspondence with analytical solutions has been excellent. For some examples a special near-field wavenumber has been added to preserve a high accuracy close to cutoff. >

Integrated receivers up to 220 GHz utilizing GaAs-mHEMT technology

The status of integrated receivers for remote sensing and communication applications from 60 GHz to higher frequencies is reviewed. Recent receiver results for silicon and III–V technologies are compared with Schottky diode receivers.

An integrated millimeterwave BCB patch antenna HEMT receiver

A new integrated millimeterwave patch antenna HEMT receiver for imaging applications is presented. The mixer element is a HEMT working in a resistive mode. We use a relatively thick layer of BenzoCycloButhene (BCB) as dielectric support for the antenna element, and to realize microstrip based circuits. At an RF of 35 GHz we obtain a minimum conversion loss of 8 dB, defined as the IF power dissipated in a 50 /spl Omega/ load divided by the available power from the patch antenna.<<ETX>>

A compact MMIC SPDT switch for 60 GHz applications

This paper presents a GaAs MMIC SPDT switch for 60 GHz applications. Insertion loss and isolation of the switch was measured to be 1 dB and 20 dB, respectively. The circuit uses only two passive HEMT devices in shunt configuration making it very compact, reciprocal and with a high power performance.

A new millimeter-wave MMIC mixer for sensor applications

A new configuration of a MMIC gate mixer associated with a dual-polarized patch antenna was experimentally investigated at 94 GHz for the first time. A 7 dB reduction in the LO power requirement was experimentally observed when compared to a previously used resistive mixer. The new configuration with its low pumping power can significantly simplify the design of the LO sensor chain compared to the ordinary mixer configuration which consumes 3-10 dBm per device to attain a sufficiently low conversion loss for a typical radar application.

A new mixer for sensor applications

A new configuration of a gate mixer associated with a dual-polarized patch antenna was experimentally investigated for the first time. A gain of 5-7 dB was obtained at local oscillator (LO) power of -17 dBm at the device terminals. The new configuration with low pumping power can significantly simplify the design of the LO sensor chain compared to the ordinary configuration which consumes 3-8 dBm per device.

A new staring 94 GHz focal plane array

A new staring 94 GHz focal plane array (4x8 pixels) multi-chip module (MCM) using a quasi-optically pumped MMIC gate mixer is presented. The new MCM with integrated microstrip antennas, matching and bias networks are manufactured using a modified MCM-D process based on 3x15 μm BCB. The active gate mixer MMIC was manufactured by OMMIC (D01PH process) and uses a 2x25 μm gate width. The 30 cm dielectric lens antenna has a F/D number of approximately unity. To minimize the spillover loss, the beamwidth of the feed antennas (microstrip antennas) was matched to the opening angle of the lens by using 2x2 subarrays for each pixel. Preliminary measurement results show a feed antenna gain of approximately 10 dBi and a conversion loss close to zero at 94 GHz, and an optimal pumping power of -2 dBm at 92.4 GHz.