Microwave coupler for a monolithic integrated circuit

Details Microwave coupler for a monolithic integrated circuit Microwave coupler for a monolithic integrated circuit

1999-10-04

2001-12-18

Pascal, Robert (Department: 2817)

Wave transmission lines and networks

Plural channel systems

Having branched circuits

C333S026000, C333S238000, C333S248000

Reexamination Certificate

active

06331807

ABSTRACT:

The invention relates to a coplanar microwave coupler and more particularly to a balanced and active coplanar microwave coupler for incorporation in a monolithic microwave integrated circuit (MMIC).
BACKGROUND OF THE INVENTION
Active microwave couplers of the combiner or divider types as incorporated in MMICs used to suffer from the drawback of being relatively bulky and difficult to integrate.
A first improvement was obtained with active couplers, known as line-unified field-effect transistors (LUFETs) using field-effect transistors (FETs) having accesses unified with uniplanar interconnections. Such couplers are described in particular in the document entitled “Divider and combiner line-unified FETs as basic circuit function modules” published in September 1990 by T. TOKUMITSU et al., pp. 1210-1226, Vol. 38, No. 9, IEEE MTT.
Unifying accesses for the transistors makes it possible to take advantage of the slots formed by the metal strips constituting the electrodes of the transistors. It is thus possible to reduce the dimensions and the complexity involved in making a coupler. This also makes it possible to increase the frequency bandwidth of MMICs made in that way. Nevertheless, the resulting electrical performance, particularly in terms of insertion gain, remains limited. Furthermore, it is not always possible to integrate such a coupler directly in a more complete balanced circuit, and as a 180° combiner in a balanced mixer, for example, since such a combiner requires inlet accesses that are floating and outlet accesses referenced to ground, which is not possible with the desired coupler.
OBJECTS AND SUMMARY OF THE INVENTION
The invention thus provides a balanced and active coplanar microwave coupler for an MMIC, comprising FETs provided with metal grid, source, and drain electrodes integrated with coplanar plane metal elements combined to constitute the inlet and outlet accesses of the coupler, wherein all of the accesses are constituted by an association comprising one or more coplanar striplines (CPS) and one or more coplanar waveguides (CPW).
In a preferred embodiment of the invention, the coupler comprises a floating, central electrode obtained by using coplanar striplines in all of the accesses.
In an embodiment of the invention, the coupler includes two inlet accesses which are constituted by two coplanar waveguides each acting on half of the transistors of the coupler under the action of signals excited in phase opposition, and an outlet access which is constituted by a coplanar stripline connected to a T-junction where the intermediate signals coming from the transistors are recombined in phase.
In an embodiment of the invention, the coupler, of the divider type, includes a floating inlet obtained by adding a CPS/CPW transition.
In an embodiment of the invention, the coupler, of the combiner type, includes a floating inlet obtained by adding a coplanar stripline upstream from an inlet CPS/CPW transition of the coupler.
In an embodiment of the invention, the number of transistors in the coupler that are fed via an inlet access is equal to two or a multiple of two, with all of the transistors having either one or in the alternative two grid fingers, thereby making it possible to improve electrical performance concerning power gain.
Finally, the invention provides a monolithic integrated circuit including a coupler having at least one of the above-mentioned characteristics.


REFERENCES:
patent: 3848198 (1974-11-01), De Brecht et al.
patent: 5105171 (1992-04-01), Wen et al.
patent: 5387547 (1995-02-01), Dougherty et al.
patent: 5698469 (1997-12-01), Mohwinkel et al.
patent: 0 880 194 A1 (1998-11-01), None
patent: WO 97/17738 (1997-05-01), None

Affiliated with

Also associated with

Rating

Microwave coupler for a monolithic integrated circuit does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Microwave coupler for a monolithic integrated circuit, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Microwave coupler for a monolithic integrated circuit will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2589741