Telecommunications – Receiver or analog modulated signal frequency converter – Frequency modifying or conversion
Patent
1996-03-27
1998-08-11
Mullen, Thomas
Telecommunications
Receiver or analog modulated signal frequency converter
Frequency modifying or conversion
333250, H04B 126
Patent
active
057941351
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
The invention relates to a millimeter wave mixer realized by windowing, the mixer being of the type that includes a substrate metallized on one side in a rectangular waveguide.
Because of today's increasing demands with regard to the efficiency of millimeter wave mixers and the simultaneous demand for increasing miniaturization and because of growing cost pressures it is necessary to implement such mixers with adapted designs in new technologies.
One technology which meets these demands was already proposed and is generally described by the term "windowing". Mixers produced with this technology usually have a substrate which is metallized on one side, with the substrate being arranged in a waveguide.
Furthermore, it is generally known that, in push-pull mixers, mixer diodes for a local oscillator (LO) signal must be connected in parallel and that the high-frequency signal which is to be mixed into the intermediate frequency position must be connected in series. In the implementation of input circuits, care must therefore be taken to match the LO source resistance to half of the real diode resistance, the signal source resistance to double the real diode resistance.
Since, during this process, both signal power and LO power are supplied by the associated waveguide--whose source resistance corresponds approximately to that of the mixer diodes--a transformation ratio between source impedance and diode impedance must be realized in the LO input circuit, which ratio is larger by the factor of 4 than in the signal input circuit. Since, in the millimeter wave frequency range, the amount of the ohmic resistance of a mixer diode is usually smaller than 10 ohms and the wave impedance of commercially available waveguides amounts to approx. 400 ohms, an impedance transformation ratio of 1:80 must be realized with the LO input circuit.
This can only be realized by means of a resonance transformation. If LO waveguides and signal waveguides are removed from one another by several wavelengths, the bandwidth of the LO input circuit is reduced very quickly. Measures to improve the LO input circuit at the location of the mixer diodes usually impact the signal input circuit.
Furthermore, it is generally known that the base impedance (impedance between terminal mass and component) must be low in order to match a low-resistance component in a broadband manner to a predetermined source impedance.
It is now desirable to transfer the advantages of windowing to further modules of the millimeter wave technique, which advantages are namely the high degree of miniaturization that is possible while simultaneously complying with or simultaneously exceeding the electrical requirements that have been standard so far (high noise immunity, broadband feature, etc.).
SUMMARY OF THE INVENTION
Therefore, it is the object of the invention to propose a small millimeter wave mixer realized by windowing which can be produced without difficulty and in a material-saving and cost-advantageous manner. Furthermore, this mixer should be a broadband mixer and be immune to noise.
According to the invention, the object is solved in that a coplanar line is carved out of the metallization of the substrate, which line divides the metallization into two parts, in that the coplanar line is guided out at the narrow sides of the waveguide, in that the coplanar line is connected to each of the two parts via a first or second diode and in that at least two slot lines are carved out of the metallization parallel to the wide sides of the waveguide.
Here, it is advantageous that the mixer according to the invention is provided with a high degree of miniaturization. This considerably reduces, for example, the fabrication costs when the mixer according to the invention is mass-produced. Further advantages are the broadband feature and noise immunity.
BRIEF DESCRIPTION OF THE DRAWINGS
In the following, the invention is represented in an exemplary manner by way of the drawings, with identical reference numerals in different figures design
REFERENCES:
patent: 3882396 (1975-05-01), Schneider
patent: 4118670 (1978-10-01), Dickens
patent: 4255730 (1981-03-01), Sekine
patent: 4276655 (1981-06-01), Kraemer et al.
patent: 4425549 (1984-01-01), Schwartz et al.
patent: 4641369 (1987-02-01), Grote et al.
patent: 4661997 (1987-04-01), Roberts
patent: 5115217 (1992-05-01), McGrath et al.
Daimler-Benz Aerospace AG
Mullen Thomas
LandOfFree
Millimeter wave mixer realized by windowing does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Millimeter wave mixer realized by windowing, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Millimeter wave mixer realized by windowing will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-403117