Masayoshi Aikawa

Broad-band monolithic microwave active inductor and its application to miniaturized wide-band amplifiers

A broadband monolithic microwave active inductor composed of two FETs and a resistor is proposed. The most significant innovation of the active inductor is considered to be a novel circuit structure which suppresses stray capacitance to yield a much higher-frequency operating range than a spiral inductor. The inductor is small and independent of the inductance value. The FET-oriented configuration allows a denser chip circuitry packing. A 0.1-10-GHz miniaturized wideband amplifier realized using the active inductors is described. >

Lossless broad-band monolithic microwave active inductors

Lossless, broadband microwave active inductors are proposed for general-purpose use in microwave circuits. These active inductors operate in a wide frequency range with very low series resistance. They are composed of a common-source cascode FET and a feedback FET which is a common-gate FET or a common-gate cascode FET. The loss can be less than 1/8 the loss of the previously proposed active inductor. The inductance value can be controlled by the external control voltage. The configuration and performance of these devices are described. >

Slot-coupled directional couplers between double-sided substrate microstrip lines and their applications

A slot-coupled microstrip directional coupler and its application to a planar multiport directional coupler (MDC) are described. This coupler can be applied to both loose coupling (e.g. 10 dB) and tight coupling (e.g. 3 dB). A four-port planar MDC fabricated by combining these couplers is described. Measured and calculated results are in agreement for both couplers. >

Low voltage, high power T/R switch MMIC using LC resonators

A T/R (transmit/receive) MMIC (monolithic microwave integrated circuit) switch for high-power/low-distortion operation at low control voltage is proposed. LC-resonant switches composed of inductors, capacitors, and switching FETs are incorporated in the TX and RX arms to provide a reverse control scheme which removes the RF voltage limitation in the transmit mode. An LC-resonant T/R switch with total periphery of 2.88 mm exhibits third IMR less than -40 dB for input power up to 28 dBm when controlled at 0 V/2 V.<<ETX>>

Novel unilateral circuits for MMIC circulators

A circuit which is equivalent to a four-port circulator with one port terminated, called a quasi-circulator, is proposed. The quasi-circulator can replace a conventional circulator even though it is not a complete circulator. Examples of novel three-port unilateral circuit modules, called quasi-circulator modules, which are the main part of the quasi-circulator are presented to realize very wide band circulators in monolithic microwave integrated circuit (MMIC) form without using ferrite materials and external magnets. The proposed modules are composed of an active out-of-phase divider and an active in-phase combiner or an active in-phase divider and an active out-of-phase combiner. The modules have many variations. All are very small and operate over a very wide frequency range. Two types of quasi-circulator modules that have very broadband operation up to X or Ku band are demonstrated. A quasi-circulator is also demonstrated. It is shown how an active circulator is realized by quasi-circulator modules. >

Three-dimensional masterslice MMIC on Si substrate

This paper describes Si based three-dimensional MMIC technology. This technology greatly improves the operating frequency of Si MMICs up to the Ku-band and makes them competitive with GaAs MMICs in the higher frequency band. An X-band amplifier and highly integrated single-chip receiver using Si bipolar transistors are demonstrated to highlight the advantages of the Si 3-D MMIC technology. Cost estimation compared with conventional GaAs 2-D MMICs is also discussed.

Divider and combiner line-unified FET's as basic circuit function modules. II

For pt.I see ibid., vol.38, no.9, p.1210-17 (1990). Applications of line-unified FETs (LUFETs) to RF signal processing elements such as multiport combiner/dividers, mixers, balanced modulators, signal path switches, and circulators are proposed and demonstrated. A 2*1 combiner monolithic microwave integrated circuit (MMIC) using an in-phase combiner LUFET and an N*N combiner/divider based on the 2*1 combiner topology are presented. A single-end mixer and a balanced mixer implemented by combining divider and combiner LUFETs are presented, and a balanced mixer LUFET is proposed. A balanced modulator which is realized by slightly changing the phase inverter LUFET configuration is presented. This modulator is also a LUFET. A signal path switch with a configuration of symmetrically combined magic T LUFETs is presented. A circulator which is a combination of in-phase and out-of-phase divider and combiner LUFETs is presented. The areas of the fabricated LUFETs and LUFET MMICs are between 0.1 and 1.5 mm/sup 2/, the average being about 0.5 mm/sup 2/. >

A low-voltage, high-power T/R-switch MMIC using LC resonators

A novel T/R switch is proposed for high-power/low-distortion operation at a low control voltage. LC-resonant switches composed of inductors, capacitors, and switch FETs are incorporated in TX and RX arms to provide a reverse control scheme that removes the rf-voltage limitation in the transmit mode, A 1.9-GHz LC-resonant T/R switch MMIC with a total FET periphery of 3.36 mm exhibits 3rd IMR less than -40 dB for an input power up to 31 dBm when controlled at a V/-2 V. This MMIC occupies an area as small as less than 2/spl times/2 mm, This will make it possible to implement advanced T/R-switches at PCS and ISM frequencies below 5 GHz. >

Lossless, broadband monolithic microwave active inductors

Lossless, broadband microwave active inductors are proposed for general-purpose use in microwave circuits. These active inductors operate in a wide frequency range with very low series resistance. They are composed of a common-source cascode FET and a feedback FET which is a common-gate FET or a common-gate cascode FET. The loss can be less than 1/8 the loss of the previously proposed active inductor. The inductance value can be controlled by the external control voltage. The configuration and performance of these devices are described.<<ETX>>

Three-dimensional MMIC technology for multifunction integration and its possible application to masterslice MMIC

We first verified that the integration level of multifunction MMICs can be easily increased three-fold by using three-dimensional (3-D) MMIC structure, in comparison to planar ones. The technology was used to build high-density masterslice MMICs on a single footprint in 2/spl times/2 mm by incorporating two levels of ground metals in the 3-D structure.