JP2006148809A - Image cancel mixer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wide-band image cancel mixer. <P>SOLUTION: The image cancel mixer has a plurality of hybrids 15 and 16 differing frequency band in the same MMIC chip and a hybrid matching a desired frequency is selected by in-chip bonding to have constitution adaptive to a wide frequency band unlike before with one kind of MMIC. Then the mixer having a very wide band can be realized. Further, components are usable in common over a wide frequency range to facilitate arrangement of components, stock management, etc., and also make it easy to design a device and so on. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a mixer, and in particular, an image formed by a microwave / millimeter wave high frequency circuit (MMIC) in which active / passive elements, functional circuits, and the like are integrally manufactured on a semiconductor substrate such as gallium arsenide (GaAs). Regarding cancellation mixer.

  Microwave and millimeter-wave wireless communication devices have a wide range of frequencies from several GHz to 60 GHz, and the number of units produced or market demand varies depending on the frequency. There are not a few stand devices. When an MMIC is used for an apparatus with such a production quantity, the production quantity of the MMIC becomes a problem.

  When manufacturing an MMIC, the minimum lot is usually one wafer. In the case of GaAs, which is currently widely used in the microwave and millimeter wave bands, the mainstream is 4 inchwafer. For example, a 1.8 mm × 0.5 mm mixer has a theoretical yield of about 7000 (p) with one 4 inchwafer.

  Therefore, when the same number of three types of mixers having different frequencies are manufactured from one wafer, about 2300p can be manufactured ideally. In this case, there is no problem as long as the required amounts of the three types of mixers are equal. However, since the demand varies depending on the frequency as described above, generally, the required amount of each mixer is not the same. That is, even if the other two types of mixers remain, if one type of mixer runs out of stock, three types of mixers are manufactured. If this happens, excess inventory will increase.

  A method of manufacturing one type of MMIC with one wafer is also conceivable. However, since the quantity manufactured at one time is large, there is a possibility of having a lot of excess inventory. Also, since the MMIC manufacturing period is usually as long as about two months, inventory management becomes more difficult.

  In this way, if different MMICs are used for each frequency, the types of MMICs increase, resulting in problems in availability, inventory management, etc., and adversely affecting delivery times and prices.

  In the conventional MMIC image canceling mixer, the band is about one octave at most, and the same chip component cannot be used if the frequency is more than doubled.

  For this reason, the MMIC image cancellation mixer requires different types of MMICs for each frequency, and the above-described problems of the radio communication apparatus in the microwave band and the millimeter wave band become obvious.

  Even if the frequency of use of the image cancellation mixer is different, if it is possible to cope with common parts, only one kind of production and inventory management is required, and the above-mentioned problems are solved.

(the purpose)
SUMMARY OF THE INVENTION The main object of the present invention is to solve the above-mentioned problems, and to provide an image cancellation mixer which can cope with common components even if the used frequency is different.
Another object of the present invention is to provide an image cancellation mixer that can be used in a wider band.
Another object of the present invention is to provide an image cancellation mixer that is easy to design and flexible.

The present invention is characterized by having a plurality of hybrids having different frequency bands on the same chip as an image canceling mixer of the MMIC in the microwave band and the millimeter wave band. Multiple hybrids with different frequency bands are built in the same MMIC chip, and a hybrid suitable for the used frequency (output frequency) is selected by bonding within the chip. Make it available. That means
The image cancellation mixer of the present invention is an MMIC image cancellation mixer in the microwave band and the millimeter wave band, and has a plurality of hybrids (for example, 15 and 16 in FIG. 1) having different frequency bands on the same chip. And having a mixer that can be selectively connected to any of the plurality of hybrids according to a use frequency (output frequency), or having a plurality of mixers respectively connected to the plurality of hybrids. To do.

  The mixer includes a nonlinear element, two input / output pads (for example, 7, 9, 9 ′ in FIG. 1) connected to the nonlinear element, and one input pad (for example, 1 in FIG. 1). It is composed of a pair of mixer circuits, and the plurality of hybrids (for example, 15 and 16 in FIG. 1) have three input / output pads (for example, 11, 13, 12, and 14 in FIG. 1), One input / output pad (for example, 7 in FIG. 1) of each mixer circuit and one input / output pad (for example, 11 and 12 in FIG. 1) of the plurality of hybrids are arranged close to each other. It is characterized by that.

  Further, the mixer is disposed between or outside at least hybrids having different nonlinear elements, the nonlinear elements are configured by anti-parallel diodes or single diodes, and the hybrid is configured by a Lange coupler to which a terminating resistor is connected. It is characterized by that.

  In the present invention, it is possible to realize a very wide band mixer by incorporating a plurality of hybrids having different frequency bands in the same MMIC chip.

  Parts can be shared over a wide frequency range where the same parts could not be used in the past, and parts arrangement and inventory management are easy.

  Furthermore, since it is possible to cope with the operating frequency by selecting the connection between the bonding pads of the image cancellation mixer or the bonding pad and the external circuit at the time of assembling the apparatus, the design of the apparatus becomes easy.

An embodiment of the image cancellation mixer of the present invention will be described in detail.
(Description of configuration)
FIG. 1 is a diagram showing a configuration of an embodiment of an image cancellation mixer of the present invention.
Reference numeral 1 denotes a bonding pad (referred to as “pad”), which is an input pad for inputting a local frequency (LO frequency) signal (LO signal), 2, 4, 6 and 10 are capacitors, 3 is a pad, 5 Is an anti-parallel diode as a nonlinear element, 8 is a microstrip line, 7, 9, 9 ', 11, 12, 13 and 14 are input / output pads, and 9 and 9' are intermediate frequencies (IF frequencies). Input / output pads for inputting / outputting the signal (IF signal), 13 and 14 are pads for inputting / outputting a high frequency (RF frequency) signal (RF signal), 15 and 16 are 3 dB hybrids, and 17 and 18 are The termination resistor 19 of the hybrid connected to one of the four input / output ports of the 3 dB hybrid, 19 is a ground.

FIG. 2 is a diagram showing an equivalent circuit of the image cancellation mixer of the present embodiment.
The image cancellation mixer according to the present embodiment includes a mixer composed of a pair of mixer circuits composed of 1 to 10, a hybrid 15 having a frequency band f0 to 2 × f0, and a hybrid 16 having a frequency band 2 × f0 to 4 × f0. It is configured. In the mixer circuit, the values of capacitors 2, 4, 6, and 10 and the length and width of the microstrip line 8 are selected so that good characteristics can be obtained at frequencies f0 to 4 × f0.

  As the circuit arrangement of the image cancellation mixer of the present embodiment, the U-shaped 3 dB hybrid 15 and the linear 3 dB hybrid 16 are respectively connected to the terminal resistors 17 and 18 so as to surround substantially the outer periphery of the chip. A pair of mixer circuits 1 to 10 constituting the mixer are arranged in the direction in which the pads 13 and 14 of the two are approaching each other, except for the capacitor 10 and the IF signal input / output pads 9 and 9 ′. In the region surrounded by the 3 dB hybrid 15, the input pads 1 are arranged close to each other, and the input / output pads 7 of the pair of mixer circuits 1 to 10 are respectively connected to the 3 dB hybrids 15 and 16. The input / output pads 11 and 12 are arranged close to each other. With such an arrangement, it is possible to form a straight line portion of the hybrid coupled line, to secure a region for connection between both ends and bonding pads, and to arrange a mixer, and to facilitate design.

  The configuration of the circuit arrangement of the image cancellation mixer is not limited to the above configuration, and the pair of mixer circuits 1 to 10 and the linear 3 dB hybrid 16 shown in FIG. It is possible to secure the same region and facilitate the design by various arrangement changes such as arranging the mixer circuits 1 to 10 so as to be outside the 3 dB hybrids 15 and 16 adjacent to each other.

In the image cancellation mixer, the mixer and the hybrid are not connected at the chip manufacturing stage. When the image cancellation mixer is assembled, the input and output pads 7 and 11 are connected when the frequency used is f0 to 2 × f0. In the case of 2 × f0 to 4 × f0, it is possible to connect the input / output pads 7 and 12 with bonding wires and connect the mixer and the hybrid.
With the configuration of the present embodiment, the frequency f0 to 4 × f0 and the band of 2 octaves can be covered with one chip.

(Description of operation)
As an example, the operation in the case of an up-converter will be described using the equivalent circuit shown in FIG. The LO frequency is fLO, the IF frequency is fIF, and the RF frequency is fRF.

  In the case of the up-converter, the LO signal input from the input pad 1 and the IF signal input from the input / output pads 9 and 9 ′ are frequency-converted by the non-linear characteristic of the anti-parallel diode 5. The IF signals input from the input / output pads 9 and 9 'have the same power and are 90 ° out of phase. At this time, the frequency component generated by the anti-parallel diode 5 and output to the input / output pad 7 is ideally (m × fLO + n × fIF) (m and n are integers and m + n is an odd number).

  FIG. 3 is a diagram showing the frequency relationship at the terminal 7. In this case, a signal of m = 2 and n = ± 1 becomes a desired signal. When the frequency to be used is within the band of the hybrid 15, the input / output pads 7 and 11 are connected by bonding wires.

  At this time, when the signal output from the input / output pad 13 is in the upper sideband (USB), the signal of the frequency (2 × fLO−fIF) is canceled and the signal of fRF = (2 × fLO + fIF) is obtained. It will be.

  When the desired frequency is higher than the frequency band of the hybrid 15 and is within the frequency band of the hybrid 16, the input / output pad 14 and the input / output pad 12 are connected by a bonding wire to connect the input / output pad 14. Thus, a signal having a desired frequency is obtained.

  The operation of the image cancel mixer described above is as follows. For the mixer circuit, the input pad 1 is used as the LO signal input, the input / output pads 9 and 9 'are used as the IF signal input, and the input / output pad 7 is used as the input signal. For the hybrids 15 and 16, the input / output pads 11 and 12 are input (inputs from the input / output pad 7), and the input / output pads 13 and 14 are RF signal outputs. Operation is the same image cancel mixer. For hybrids 15 and 16, input / output pads 13 and 14 are used as RF signal inputs, input / output pads 11 and 12 are used as outputs, and mixer circuits are used as inputs. The input pad 1 is used as the LO signal input, the input / output pad 7 is used as the input (input from the input / output pads 11 and 12), and the input / output pad 9 is used. 9 'can operate as a down-converter by the output of the IF signal.

(Embodiment 2)
FIG. 4 is a diagram showing another embodiment of the image cancellation mixer of the present invention. In this example, one mixer is provided for one hybrid circuit. The advantage of the second embodiment is that there is no need to connect the mixer and the hybrid by in-chip bonding, and the frequency band of the mixer can be made narrower than in the first embodiment in which the mixer is shared. It is to be able to configure a mixer that is more efficient than the first mode. In the case of the second embodiment, the chip area is larger than that in the first embodiment, but the ratio is suppressed to about 20%. Therefore, when the performance is more important than the price, the method of the second embodiment is adopted. Is possible.

  1, 51 are input / output pads for inputting an LO signal, 2, 52, 4, 54, 6, 56, 10, 60 are capacitors, 3, 53 are pads, and 5, 55 are anti-parallel diodes as nonlinear elements. 8, 58 are microstrip lines, 9, 59, 9 ′, 59 ′ are I / O pads for inputting / outputting IF signals, 13, 14 are I / O pads for inputting / outputting RF signals, and 15, 16 Is a 3 dB hybrid, 17 and 18 are termination resistors of the hybrid connected to one of the 4 I / O ports of the 3 dB hybrid, and 19 is a ground.

  The image cancellation mixer according to the second embodiment is a hybrid of a first pair of mixer circuits (first mixer) composed of 1 to 6, 8, and 10 and a predetermined frequency band (for example, f0 to 2 × f0). 16 and 51 to 56, 58, 60, and a second pair of mixer circuits (second mixer) and a hybrid 15 of a predetermined frequency band (for example, 2 × f0 to 4 × f0). Yes. Here, in the first and second mixers, the value of each capacitor and the length and width of the microstrip line are selected so that good characteristics can be obtained at the respective frequencies.

  In the second embodiment, the U-shaped 3 dB hybrid 15 and the linear 3 dB hybrid 16 are respectively connected to the terminating resistors 17 and 18 and the input / output pads 13 and 14 so as to surround the substantially outer periphery of the chip. Are arranged in directions approaching each other. The first mixer is arranged in a region surrounded by the 3 dB hybrid 16 and the 3 dB hybrid 15 except for the capacitor 10 and the input / output pads 9 and 9 ′, and the electrode of the capacitor 6 serving as an output port of the mixer is provided. The input / output pads of the 3 dB hybrid 16 are connected. The second mixer is arranged in a region surrounded by the 3 dB hybrid 16 and the 3 dB hybrid 15 except for the capacitor 60, the microstrip line 58 and the input / output pads 59 and 59 ', and the output port of the mixer circuit. The electrode of the capacitor 56 is connected to the input / output port of the 3 dB hybrid 16.

  In the second embodiment, one input pad 1, 51 of each of the first and second mixers, and two input / output pads 9, 9 ′, 59, 59 ′ are bonded to each other. By performing selective connection with an external circuit or the like, it is possible to cope with one type of MMIC even if the used frequency is different.

(Other embodiments)
In the above embodiment, an example in which an anti-parallel diode in which a diode is connected in antiparallel is used as a nonlinear element of an image cancel mixer has been described. However, a single diode that uses a single diode instead of an anti-parallel diode is used. It can also be configured as a fundamental mixer.

  In the first and second embodiments described above, the number of hybrids can be increased to 3 or more by setting the number of hybrids to three or more. As a hybrid configuration, microwave signals, millimeter waves can be used. It is preferable to use a Lange coupler in which four input / output ports are connected to a coupled line composed of a plurality of conductors for coupling signals.

  Further, in the second embodiment, an example in which the number of hybrids and mixers is the same is shown. However, the number of mixers is smaller than the number of hybrids, and the connection between the mixers and hybrids is selectively connected as in the first embodiment. It is obvious that it can be configured.

It is a figure which shows the structure of one Embodiment of the image cancellation mixer of this invention. It is a figure which shows the equivalent circuit of the image cancellation mixer of this Embodiment. FIG. 6 is a diagram showing a frequency relationship at a terminal 7. It is a figure which shows other embodiment of the image cancellation mixer of this invention.

Explanation of symbols

1 LO signal input pads 2, 4, 6, 10 Capacitor 3 Bonding pads 7, 11, 12 Input / output pads 5 Anti-parallel diode 8 Microstrip line 9 IF signal input / output pads 13, 14 RF Signal input / output pad 15, 16 3dB hybrid 17, 18 Hybrid termination resistor 19 Ground

Claims (9)

In the MMIC image cancellation mixer in the microwave band and the millimeter wave band,
An image cancel mixer comprising a plurality of hybrids having different frequency bands on the same chip.   The image cancel mixer according to claim 1, further comprising a mixer that can be selectively connected to any of the plurality of hybrids according to a use frequency.   The image cancellation mixer according to claim 1, further comprising a plurality of mixers respectively connected to the plurality of hybrids.   The mixer is composed of a non-linear element, a pair of mixer circuits having two input / output pads connected to the non-linear element and one input pad, and the plurality of hybrids have three input / output pads. 4. The image cancellation mixer according to claim 2, further comprising a pad.   5. The image cancel mixer according to claim 4, wherein one input / output pad of each mixer circuit and one input / output pad of the plurality of hybrids are arranged close to each other.   5. The image canceling mixer according to claim 4, wherein the mixer is arranged between hybrids having at least nonlinear elements.   The image canceling mixer according to claim 4, wherein the nonlinear element includes an anti-parallel diode.   The image cancel mixer according to claim 4, wherein the nonlinear element includes a single diode.   The image cancellation mixer according to claim 1, wherein the hybrid includes a Lange coupler to which a terminating resistor is connected.

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