JP2006186634A - Micro-vibrator, semiconductor device, and communication device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress undesired output due to reflection of an elastic wave from a border of electrostatically driven type vibrator groups of a micro-vibrator consisting of the vibrator groups. <P>SOLUTION: The vibrator groups 341 and 342 constituted by arraying a plurality of vibrator elements 33 are arranged on a substrate 32; and each vibrator element 33 has a beam 47 which has both ends supported on the substrate 32 and vibrates with static electricity in a direction opposed to the substrate 32 and border lines 351 and 352 of the vibrator groups 341 and 342 form a non-square shape. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a micro vibrator serving as an element such as a signal filter, a mixer, and a resonator, a semiconductor device having the micro vibrator, and a communication device using a bandpass filter using the micro vibrator.

  A micro vibrator manufactured using a micro electro mechanical systems (MEMS) technique is known. Research institutes such as the University of Michigan have proposed the use of this micro vibrator as a high frequency filter (see Non-Patent Document 1).

  FIG. 18 shows an outline of a micro vibrator constituting the above-described high-frequency filter, that is, an electrostatic drive beam type vibrator. The vibrator 1 has an input-side wiring 4 and an output electrode 5 made of, for example, polycrystalline silicon formed on a semiconductor substrate 2 with an insulating film 3 interposed therebetween. The so-called beam (beam) 7 is formed. The beam 7 is connected to the input side wiring layer 4 across the bridge so as to be supported by anchor portions (support portions) 8 [8A, 8B] at both ends. The beam 7 becomes an input electrode. An input terminal t1 is derived from the input side wiring layer 4, and an output terminal t2 is derived from the output electrode 5. In this vibrator 1, a high frequency signal S1 is supplied to the beam 7 through the input terminal t1 in a state where the DC bias electrode V1 is applied between the beam 7 and the ground. That is, when the DC bias voltage V1 and the high frequency signal S1 are supplied from the input terminal t1, the beam 7 having the natural frequency determined by the length vibrates with the electrostatic force generated between the output electrode 5 and the beam 7. By this vibration, a high-frequency signal corresponding to the time variation of the capacitance between the output electrode 5 and the beam and the DC bias voltage is output from the output electrode 5 (accordingly, the output terminal t2). The high frequency filter outputs a signal corresponding to the natural frequency (natural frequency) of the beam 7.

  On the other hand, when a large number of vibrators are arranged on a substrate such as a semiconductor substrate or an insulating substrate and configured to perform signal processing, the signal quality when the signal processing is performed is ensured. From the standpoint, there are no examples that have been examined and verified regarding the appropriateness and inappropriateness of how to arrange the transducers.

C.T.-Nguyen, Micromechanicalcomponents for miniaturized low-power communications (invited plenary), proceedings, 1999 IEEE MTT-S International Microwave Symposium RF MEMS Workshop, June, 18,1999, pp, 48-77,

  FIG. 17 shows another configuration of the electrostatic drive type vibrator as the prior art. For example, the vibrator 11 is formed with an input electrode 14 and an output electrode 15 on a semiconductor substrate 12 with an insulating film 13 interposed therebetween. The vibrator 11 is opposed to the input electrode 14 and the output electrode 15 and sandwiches a space 16 to become a vibration plate. Electrodes, so-called beams (beams) 17 are formed. The beam 17 straddles the input / output electrodes 14, 15 on the bridge and is connected to a wiring layer 18 disposed outside the input / output electrodes 14, 15 at both ends with anchor portions (support portions) 19 [19 A, 19 B. ] Are integrally supported. An input terminal t1 is derived from the input electrode 14, and a high frequency signal S1 is input through the input terminal t1. An output terminal t2 is derived from the output electrode 15. A required DC bias voltage V1 is applied to the beam 17.

  In this vibrator 11, when a high-frequency signal S 1 is input to the input electrode 14, the beam 17 resonates due to an electrostatic force generated between the beam 17 to which the DC bias voltage V 1 is applied and the input electrode 14, and the target is output from the output electrode 15. A high frequency signal having a frequency is output. According to the micro-vibrator 11, since the opposing area of the input / output electrodes 14 and 15 is small and the interval between the input / output electrodes 14 and 15 can be increased, the parasitic between the input / output electrodes is smaller than that of the vibrator 1 of FIG. The capacity Co is reduced. Therefore, the signal that directly passes through the parasitic capacitance Co between the input / output electrodes 14 and 15, that is, the noise component is reduced, and the SN ratio of the output signal is improved.

  On the other hand, as shown in FIG. 16, a transducer element 21 having a plurality of (so-called many) transducers (hereinafter referred to as transducer elements), for example, input / output electrodes 14 and 15 as lower electrodes and a beam 17 on the same substrate. [21A, 21B, 21C] are configured as a group of vibrators connected in parallel with the input / output electrodes 14 and 15 in common, and can be applied to a high-frequency device by reducing the total synthetic impedance. Proposed.

  By the way, when the RF signal is input to the electrostatic drive type vibrator group and the resonance of the vibrator group occurs, if the resonance characteristics of the vibrator elements arranged adjacent to each other are approximately the same, vibration is generated. Collective vibration of the vibrator group occurs due to interference between the child elements.

  As shown in FIG. 15, the individual transducer elements 21 are the beams (beams) 17 that are electrically driven as described above, and the input / output electrodes 14 that are the lower electrodes provided away from the beams 17. 15 is driven. The vibration is excited in a direction perpendicular to the substrate 22. For this reason, the reaction force F is applied to the input / output electrodes 14 and 15 and the anchor portions 19 [19A and 19B], and these portions become vibration sources when viewed from the substrate 22 side, and elasticity generated from a plurality of vibration sources. Waves propagate together in the substrate. The substrate vibration generated in this manner excites the transducer element.

  As shown in FIG. 13, a vibrator group 24 in which a plurality (including many) of vibrator elements 21 arranged in a certain plane including the substrate 22 are connected in parallel is regarded as an elastic body. Can do. The input electrode 14, the output electrode 15, and the DC bias supply line 23 are formed in common for each transducer element 21. Therefore, as shown in FIGS. 13 and 14, when the shape of the boundary line 25 of the transducer group 24 is a parallelogram, the elastic wave is reflected by the shape of the boundary line 25 of the transducer group 24. The reflected elastic wave becomes a standing wave 26, and a resonance state different from the characteristics of the individual transducer elements generally occurs. For this reason, in the vibrator group designed based on the characteristics of the individual vibrator elements, noise is generated for a desired signal output, or ripple is generated due to signal interference. It is extremely difficult to accurately simulate the vibration characteristics of such a complex system and incorporate it as a design. Therefore, it is required to find out the structure, arrangement, and wiring method of the vibrator group that suppresses such unnecessary output.

  In view of the above-described points, the present invention provides a micro vibrator that suppresses unnecessary output caused by reflection of elastic waves from the boundary of the vibrator group, a semiconductor device including the micro vibrator, and the micro vibration. An object of the present invention is to provide a communication device including a child as a signal filter.

  The micro vibrator according to the present invention includes a vibrator group in which a plurality of vibrator elements are arranged on a substrate, and each vibrator element is supported on the substrate at one end or both ends by electrostatic force. It is characterized by having beams that vibrate in opposite directions, and the boundary line of the transducer group forms a non-rectangular shape.

  The boundary line is a line connecting the centroids of the transducer elements on the outermost periphery of the transducer group, and the average value of the distance between the centroids of adjacent beams in the long side length direction and the short side length direction of the beam Is defined by a line in which unevenness of 1/2 or less of the larger value is regarded as a straight line. The polygon formed by the boundary line is selected so that the number of sides is the smallest and the area is closest to the area of the polygon formed by connecting the centroids of all the transducers on the outermost circumference of the transducer group. The boundary line is defined as the outer periphery of the polygon thus determined.

  The non-square shape of the boundary line of the transducer group is preferably a shape in which the lengths cut by the boundary line of two parallel lines parallel to any of the boundary lines are not equal to each other.

  A triangle can be selected as the shape of the boundary line.

  The plurality of transducer elements constituting the transducer group can be regularly arranged on the substrate.

  The vibrator element can be configured to be excited in the second harmonic vibration mode.

  A semiconductor device according to the present invention includes the above-described micro vibrator.

  A communication apparatus according to the present invention is characterized in that, in a communication apparatus provided with a filter that limits a band of a transmission signal and / or a reception signal, the filter using the above-described micro vibrator is used as a filter.

  According to the micro vibrator according to the present invention, by making the boundary line of the vibrator group into a non-rectangular shape, the elastic wave generated in the substrate is reflected by the boundary line of the vibrator group during the operation of the vibrator group. Thus, it is possible to suppress the standing waves induced by the convergence, and a small number of vibration modes over a group of vibrators having a large amplitude. That is, in a transducer group in which a plurality of transducer elements are arranged, for example, generation of a standing wave having a large amplitude generated across the transducer group due to vibration energy leaking from an anchor portion that supports a beam (beam) is suppressed. The For this reason, the unnecessary signal and noise level of this vibrator group can be lowered. Therefore, if the micro vibrator according to the present invention is used as a constituent element, various devices having excellent characteristics with little noise, such as a signal processing apparatus, can be realized.

  As the non-rectangular shape of the boundary line of the transducer group, the lengths cut by the boundary line of two parallel lines parallel to one of the boundary lines may be different from each other. Thereby, generation | occurrence | production of the said standing wave can be suppressed reliably.

  When the shape of the boundary line of the transducer group is a triangle, the generation of the standing wave can be reliably suppressed, and the occupied wafer area of the transducer group can be minimized. Thus, stray capacitance due to wiring can be minimized.

  Further, when the transducer elements of the transducer group are regularly arranged, the occupied wafer area of the transducer group can be kept to the minimum necessary, and the stray capacitance generated in connection with the wiring can be minimized. . For this reason, the performance and low price of the signal processing device can be realized.

  According to the semiconductor device of the present invention, a semiconductor device having excellent characteristics with less noise can be provided by using the above-described micro-vibrator of the present invention as a vibrator that is a component of the semiconductor device.

  According to the communication apparatus according to the present invention, by using the filter by the micro vibrator according to the present invention as the bandpass filter, excellent filter characteristics with less noise can be obtained, and a highly reliable communication apparatus can be provided.

  Embodiments of the present invention will be described below with reference to the drawings.

  In this embodiment, in the group of transducers arranged in parallel on the same substrate, the shape of the boundary of the transducer group is not reduced in order to suppress unnecessary output due to reflection of elastic waves from the boundary of the transducer group. Make it square. In this way, in the present embodiment, the propagation distance of the elastic wave within the transducer group is effectively increased to make it difficult for the elastic standing wave to stand.

  The vibrator group includes a plurality of (including many) beam-type vibrator elements that are electrostatically driven as described above. There is no limitation on the arrangement of the individual vibrator elements. For example, they may be arranged irregularly. However, in this case, various troubles in process management occur when an attempt is made to arrange a plurality of transducer elements on a substrate. Fabrication of a mask for lithography is extremely troublesome, and when the wafer is planarized by chemical mechanical polishing (CMP), non-uniform polishing amount occurs. Moreover, the utilization efficiency of a wafer deteriorates and the element becomes expensive. In light of these circumstances, in reality, the arrangement of the transducer elements must be regular. An example of the simplest shape of the non-square transducer group boundary line under such a premise is a triangle.

  As the non-square, a parallelogram, a triangle other than a regular polygon, a quadrangle, or a polygon can be used. Typically, the shape is not a square or a long rectangle, but a distorted shape. As shown in FIGS. 4A and 4B, the preferred non-square shape is a beam (beam) of at least the transducer element 33 parallel to any of the boundary lines 35 surrounding the transducer group 34 in which the plurality of transducer elements 33 are arranged. ), The lengths X1 and X2 cut by the boundary line 35 of the two parallel lines 101 and 102 separated by a distance exceeding the length a) are not equal. A typical example is a triangle. The trapezoid is not the non-rectangular shape defined here, but if there is a sufficient difference in the length of the upper base and the lower base, an effect approximately equal to that of the non-rectangular shape can be obtained.

  As shown in FIG. 5, the boundary line 35 is a curve that connects the center of gravity of the transducer element 33 in the outermost peripheral portion of one transducer group 34, that is, the center O of the beam. As shown in FIG. 6, the boundary line 35 is regarded as a straight line ignoring irregularities that are equal to or less than ½ of the average value of the larger distance between the beams b (b1, b2). That is, the boundary line 35 is determined as follows. A polygon 81 formed by connecting the centroids of all transducer elements 33 located on the outermost periphery (that is, corresponding to the centroid of the beam 47) is obtained. Then, the distance c (c1, c2) between the center of gravity of the transducer element 33 and the boundary line 35 is such that the number of sides of the polygon formed by the boundary line 35 is minimized. Satisfy the condition of ½ of the average center-of-gravity distance in the long side length direction of the child element or 1/2 of the average center-of-gravity distance of the adjacent transducer element 33 in the length direction of the short side of the element, whichever is greater Set. From the obtained polygon, the area of the transducer element 33 having the area closest to the area of the polygon 81 formed by connecting the centers of gravity of all the transducer elements 33 on the outermost periphery of the transducer group is connected. Is selected as a boundary line 35.

  FIG. 1 shows a conceptual embodiment of a micro vibrator according to the present invention. The transducer elements targeted in this embodiment are microscale and nanoscale elements. In the present embodiment, as an example, electrostatic drive with a mechanical resonance frequency of 100 MHZ configured by arranging an input electrode and an output electrode that are lower electrodes on a substrate and a beam that supports both ends to be a vibration element is arranged. Let's take up a group of type oscillators.

  As shown in FIG. 1, the micro-vibrator 31 according to the present embodiment has a large number of electrostatically driven vibrations on a substrate, in this example, a substrate 32 having an insulating film formed on the surface of a high-resistance silicon substrate. In this example, two transducer groups 34 [341, 342] arranged by arranging the child elements 33 are arranged.

Within each transducer group 34 [341, 342], a large number of transducer elements 33 are connected in parallel, and both transducer groups 341 and 342 are connected in parallel. Each transducer group 341 and 342 is formed to have a non-square shape, in this example, an unequal triangular shape having different lengths of three sides, and a right-angled triangular boundary line 35 [351, 532] in the drawing. Both boundary lines 351 and 352 are separated by a distance W1 at which elastic waves generated in the substrates 32 of the respective transducer groups 341 and 342 do not propagate to each other. Further, the right-angled triangle boundary lines 351 and 352 are formed so that the oblique sides of the triangles face each other so that the transducer group 34 [341, 342] can be arranged in a compact manner.
In FIG. 1, for ease of understanding, the number of transducer elements 33 included in the boundary lines 351 and 352 is omitted, but in reality, a large number of transducer elements 33 are arranged. .

  The transducer elements 33 in the transducer group 34 [341, 342] are arranged with regularity. Each transducer element 33, which will be described later with reference to FIG. 2, includes an input electrode 43, an output electrode 44, and a wiring layer 45, which are lower electrodes, and a vibrating electrode with both ends supported by the wiring layer 45. And a beam 47. Each transducer element 33 has its input electrode 43 connected to a common input wiring 36 formed on the substrate, its output electrode 44 connected to a common output electrode wiring 37 formed on the substrate, and its beam 47 They are connected in parallel so as to be connected to a common DC bias feed line 38 formed on the substrate.

As shown in FIG. 2, each transducer element 33 includes an input electrode 43 and a lower electrode on a substrate 32 on which an insulating film (for example, a silicon oxide film) 42 is formed on the surface of a silicon substrate 41. An output electrode 44 and a wiring layer 45 [45A, 45B] on both sides sandwiching the input / output electrodes 43, 44 are formed, and a beam (as a vibration electrode facing the input / output electrodes 43, 44 across the space 46) (Beam) 47 is arranged. The beam 47 is supported by an anchor portion (support portion) 48 [48A, 48B] whose both ends are electrically and mechanically connected to the wiring layer 45 [45A, 45B]. This beam 47 is formed in a so-called doubly supported beam structure.
In the transducer element 33, as described above, when a DC bias voltage is applied to the beam 47 and, for example, an RF wave frequency signal is input to the input electrode 43, the beam 47 resonates and an RF signal having a target frequency is output to the output electrode 44. Is output. The vibrator element 33 resonates in a second harmonic vibration mode 49 as shown in FIG.

Next, a manufacturing method of the micro vibrator according to the present embodiment will be described with reference to FIGS. This figure shows a cross-sectional structure taken along the line AA 'of FIG. The process specifications are the same as those used in the normal CMOS fabrication process.
First, as shown in FIG. 7A, a substrate 32 in which a composite film 52 of, for example, a silicon oxide thin film (HDP film: High Density Plasma oxide film) and a silicon nitride thin film is formed on the upper surface of a high resistance silicon substrate 51 as an insulating film. Prepare. In this example, a composite film 52 having a thickness of about 200 nm is formed. Subsequently, a conductive film, for example, a conductive polycrystalline silicon thin film (PDAS film: Phosphorus doped amorphous silicon) 53 is formed on the composite film 52 to a required film thickness, in this example, about 380 nm.

  Next, as shown in FIG. 7B, a resist mask is formed, and the polycrystalline silicon thin film 53 is selectively removed by, for example, a dry etching method through this resist mask, so that an input electrode 43 and an output electrode which are lower electrodes are removed. 44 and a wiring layer 45 [45A, 45B] also serving as a beam fixing portion.

  Next, as shown in FIG. 7C, the formed input electrode 43, output electrode 44, and wiring layer 45 [45A, 45B] are backfilled with an insulating film such as a silicon oxide film (HDP film) 54, and a chemical mechanical polishing method is performed. The surface is planarized by (CMP) to expose the surfaces of the input electrode 43, the output electrode 44, and the wiring layer 45 [45A, 45B].

  Next, as shown in FIG. 7D, a sacrificial layer 55 having a required thickness corresponding to the distance between the input electrode 43 and the output electrode 44 and the beam is formed on the surface. In this example, a sacrificial layer 55 is formed of a silicon oxide thin film (LP-TEOS film) having a thickness of about 50 nm.

  Next, as shown in FIG. 8E, a polycrystalline silicon thin film 56 having a thin film thickness of, for example, about 20 nm is formed on the sacrificial layer 5 as needed, and then the polycrystalline silicon thin film 56 and the sacrificial layer 55 are dried, for example. Through holes 56 [56A, 56B] reaching both wiring layers 45 [45A, 45B] are selectively removed by etching using an etching method.

  Next, as shown in FIG. 8F, a polycrystalline silicon film (PDAS film) 57 is formed on the sacrificial layer 55 having the polycrystalline silicon thin film 56 on the surface until the required thickness is reached. Subsequently, the polycrystalline silicon film 57 is patterned by a dry etching method to form a beam 47 having both ends connected to the wiring layers 45A and 45B. In this case, the portions extending from both ends of the beam 47 and connected to the wiring layers 45A and 45B, that is, the portions in the through holes 56A and 56B become the anchor portions (support portions) 48 [48A and 48B] of the beam 47.

  Next, a conductive film, for example, an aluminum silicon (Al-Si) thin film, which becomes wirings 36, 37, and 38 and pads (not shown) in FIG. After the formation, unnecessary aluminum silicon film and sacrificial layer 55 are selectively removed using, for example, a hydrogen fluoride solution (DHF). Thereby, as shown in FIG. 8G, the transducer element 33 having a space 46 of 50 nm between the input electrode 43 and the output electrode 44 and the beam 47 is formed. At the same time, wiring, that is, input wiring 36, output wiring 37, and DC bias power supply line 38 are formed. As a specific example of the approximate dimensions of the transducer element 33, as shown in FIG. 8G, the second harmonic is obtained by setting the beam length L to 13.2 μm, the beam thickness t to 1 μm, and the space h to 50 nm. The transducer element 33 is designed such that the resonance frequency when is excited is approximately 100 MHz. In this way, the target micro vibrator 31 is obtained.

  According to the micro vibrator 31 according to the present embodiment, the shape of the boundary line 35 [351, 352] of the vibrator group 34 [341, 342] is changed to a non-rectangular shape, for example, an unequal triangular shape. As shown, the elastic waves 50 and 50 ′ generated in the substrate 32 during operation are reflected at the boundary 35 of the transducer group 34 [341 and 342] but do not converge to one standing wave. That is, the elastic wave 50 is suppressed by the mutual interference of the reflected waves reflected by the boundary line 35. In this way, it is possible to suppress the occurrence of standing waves generated across the transducer group 34 [31, 342] due to the vibration energy leaking from the anchor portion 32 during the operation of the micro vibrator. Therefore, unnecessary signals and noise levels of the transducer group (so-called parallel resonators) 34 [341, 342] can be lowered. That is, when the micro vibrator 31 according to the present embodiment is used as a constituent element, various devices having excellent characteristics with little noise, such as a signal processing apparatus, can be realized.

  In addition, when the individual transducer elements 33 are regularly arranged, the occupied wafer area of the transducer group 34 [341, 342] can be minimized, so that the stray capacitance generated in connection with the wiring is minimized. Can be limited. Further, by making the shape of the vibrator group 34 a right triangle as shown in the figure, the occupied wafer area can be minimized, and also in this respect, the stray capacitance generated in connection with the wiring can be minimized. it can. Therefore, it is possible to improve the performance of the signal processing device and reduce the price.

  In the micro vibrator 31 of FIG. 1, the vibrator element 33 of the second harmonic vibration mode 49 shown in FIG. 2 is used, but vibrator elements of other vibration modes can also be applied. For example, as shown in FIG. 9, an output electrode 62 serving as a lower electrode is provided on a substrate 61, and a beam 63 that is a vibrating electrode that is supported at both ends by anchor portions 66 and receives a DC bias and an input signal. The vibrator element 67 having the primary vibration mode 64 can be applied. Further, as shown in FIG. 10, for example, output electrodes 72 are arranged on both sides of the substrate 51 with the input electrode 71 interposed therebetween, and both ends of the output electrode 72 are supported by the anchor portion 74 so as to face the input electrode 71 and the output electrode 72. A transducer element 76 of the third harmonic vibration mode 75 formed by arranging 73 can be applied. Further, as shown in FIG. 11, for example, an input electrode 71 and an output electrode 72 which are lower electrodes are arranged on the substrate 61 so as to be widely separated from each other, and a beam 73 is opposed to the input electrode 71 and the output electrode 72. It is possible to apply a transducer element 77 of the third harmonic vibration mode 75 that is arranged.

  In the above example, a transducer element having a beam with a cantilever beam structure is used, but a transducer element having a beam with a cantilever beam structure may be used.

In another embodiment according to the present invention, a signal filter, a mixer, a resonator, a SiP (system in package) device module including the same, a SoC (system A semiconductor device such as an on-chip device module can be configured.
According to the semiconductor device of this embodiment, since the micro vibrator having excellent characteristics with less noise is provided, a highly reliable semiconductor device can be provided.

  The micro vibrator composed of the electrostatic drive type vibrator group of the above-described embodiment can be used as a band signal filter such as a high frequency (RF) filter and an intermediate frequency (IF) filter.

  The present invention provides a communication device that communicates using electromagnetic waves, such as a mobile phone, a wireless LAN device, a wireless transceiver, a TV tuner, a radio tuner, etc., configured using the filter by the micro vibrator of the above-described embodiment. can do.

Next, a configuration example of a communication apparatus to which the above-described filter according to the embodiment of the present invention is applied will be described with reference to FIG.
First, the configuration of the transmission system will be described. I-channel transmission data and Q-channel transmission data are supplied to digital / analog converters (DACs) 201I and 201Q, respectively, and converted into analog signals. The converted signal of each channel is supplied to band pass filters 202I and 202Q to remove signal components other than the band of the transmission signal, and the outputs of the band pass filters 202I and 202Q are supplied to the modulator 210. Supply.

  The modulator 210 supplies the frequency signals corresponding to the transmission frequency supplied from the PLL (phase-locked loop) circuit 203 for transmission to the mixers 212I and 212Q via the buffer amplifiers 211I and 211Q for each channel. The signals are mixed and modulated, and both mixed signals are added by an adder 214 to form a single transmission signal. In this case, the signal phase of the frequency signal supplied to the mixer 212I is shifted by 90 ° by the phase shifter 213 so that the I channel signal and the Q channel signal are orthogonally modulated.

  The output of the adder 214 is supplied to the power amplifier 204 via the buffer amplifier 215 and amplified so as to have a predetermined transmission power. The signal amplified by the power amplifier 204 is supplied to the antenna 207 via the transmission / reception switch 205 and the high frequency filter 206, and is wirelessly transmitted from the antenna 207. The high frequency filter 206 is a band pass filter that removes signal components other than the frequency band transmitted and received by the communication apparatus.

  As a configuration of the reception system, a signal received by the antenna 207 is supplied to the high frequency unit 220 via the high frequency filter 206 and the transmission / reception switch 205. In the high frequency unit 220, the received signal is amplified by a low noise amplifier (LNA) 221 and then supplied to the band pass filter 222 to remove signal components other than the received frequency band, and the removed signal is buffer amplifier 223. To the mixer 224. Then, the frequency signals supplied from the channel selection PLL circuit 251 are mixed, a signal of a predetermined transmission channel is used as an intermediate frequency signal, and the intermediate frequency signal is supplied to the intermediate frequency circuit 230 via the buffer amplifier 225.

  The intermediate frequency circuit 230 supplies the supplied intermediate frequency signal to the band pass filter 232 via the buffer amplifier 231, removes signal components other than the band of the intermediate frequency signal, and automatically removes the removed signal. The signal is supplied to an adjustment circuit (AGC circuit) 233 to obtain a signal with a substantially constant gain. The intermediate frequency signal whose gain has been adjusted by the automatic gain adjustment circuit 233 is supplied to the demodulator 240 via the buffer amplifier 234.

  The demodulator 240 supplies the supplied intermediate frequency signal to the mixers 242I and 242Q via the buffer amplifier 241, mixes the frequency signal supplied from the intermediate frequency PLL circuit 252, and receives the received I channel signal. The component and the Q channel signal component are demodulated. In this case, the I-signal mixer 242I is supplied with a frequency signal whose signal phase is shifted by 90 ° by the phase shifter 243, and the quadrature-modulated I-channel signal component and Q-channel signal component. Is demodulated.

  The demodulated I channel and Q channel signals are supplied to band pass filters 253I and 253Q via buffer amplifiers 244I and 244Q, respectively, to remove and remove signal components other than I channel and Q channel signals. The obtained signals are supplied to analog / digital converters (ADC) 254I and 254Q, sampled and converted into digital data, and I-channel received data and Q-channel received data are obtained.

  In the configuration described so far, band limiting is performed by applying the filter of the configuration of the above-described embodiment as a part or all of each band pass filter 202I, 202Q, 206, 222, 232, 253I, 253Q. Is possible.

  According to the communication apparatus of the present invention, since a filter having excellent characteristics with little noise is used, a highly reliable communication apparatus can be provided.

  In the example of FIG. 12, each filter is configured as a band pass filter. However, a low pass filter that passes only a frequency band lower than a predetermined frequency, or a frequency band that is higher than a predetermined frequency is used. The high-pass filters may be configured to pass, and the filters of the configurations of the above-described embodiments may be applied to these filters. In the example of FIG. 12, the communication device performs wireless transmission and reception, but may be applied to a filter included in a communication device that performs transmission and reception via a wired transmission path, and only transmission processing is performed. The filter having the configuration of the above-described embodiment may be applied to a filter included in a communication device that performs or a communication device that performs only reception processing.

It is a schematic block diagram which shows one Embodiment of the micro vibrator based on this invention. FIG. 2 is a cross-sectional view of the transducer element taken along the line AA ′ in FIG. 1. It is explanatory drawing of the reflection state of the elastic wave in the board | substrate which generate | occur | produced in the vibrator | oscillator group used for description of this invention. A and B are explanatory views for explaining the shape of the boundary line of the vibrator group according to the present invention. It is an enlarged view which shows the shape of the vibrator | oscillator group which concerns on embodiment of this invention, and its boundary line. It is explanatory drawing of the boundary line of the vibrator group of this invention. A to D are manufacturing process diagrams (part 1) illustrating an embodiment of a method of manufacturing a micro vibrator according to the present embodiment. E to G are manufacturing process diagrams (part 2) illustrating an embodiment of a method of manufacturing a micro vibrator according to the present embodiment. It is a schematic block diagram which shows other embodiment of the vibrator | oscillator element which concerns on this invention. It is a schematic block diagram which shows other embodiment of the vibrator | oscillator element which concerns on this invention. It is a schematic block diagram which shows other embodiment of the vibrator | oscillator element which concerns on this invention. It is a block diagram which shows one Embodiment of the communication apparatus which concerns on this invention. It is a block diagram of a vibrator group according to a comparative example. It is explanatory drawing explaining that a standing wave generate | occur | produces in the vibrator | oscillator group of FIG. It is explanatory drawing explaining that an elastic wave generate | occur | produces in a board | substrate at the time of operation | movement of a vibrator element. It is a block diagram which shows the example of the micro vibrator | oscillator which arranged the some vibrator | oscillator in parallel. It is a block diagram which shows the conventional electrostatic drive type | mold vibrator. It is a block diagram which shows the electrostatic drive type vibrator | oscillator based on a prior art.

Explanation of symbols

31 .. Micro vibrator, 32 .. Substrate, 33 .. Vibrator element, 34 [341, 342] .. Vibrator group, 35 [351, 352] ... Border line, 36 Input wiring, 37 · Output wiring, 38 ·· DC bias feed line, 41 · · Silicon substrate, 42 · · Insulating film, 43 · · Input electrode, 44 · · Output electrode, 45 [45A, 45B] · · Wiring layer, 46 · · Space, 47 ··· Beam (beam), 48 [48A, 48B] · · Anchor, 49 · · Second harmonic wave, 50 · · Elastic wave

Claims (9)

A vibrator group in which a plurality of vibrator elements are arranged on a substrate is arranged,
Each transducer element has a beam that is supported on the substrate at one end or both ends and vibrates in a direction facing the substrate with electrostatic force,
A micro vibrator having a non-square shape in a boundary line of the vibrator group. The boundary line is a line connecting the centroids of the transducer elements at the outermost periphery of the transducer group, and the average distance between the centroids of adjacent beams in the long side length direction and the short side length direction of the beams. The micro-vibrator according to claim 1, wherein the micro-vibrator is defined by a line in which irregularities of 1/2 or less of the larger value are regarded as straight lines. The non-square shape of the boundary line of the transducer group is a shape in which the lengths cut by the boundary line of two parallel lines parallel to any of the boundary lines are not equal to each other. The micro vibrator according to claim 1. The micro vibrator according to claim 1, wherein a shape of a boundary line of the vibrator group is a triangle. The micro vibrator according to claim 1, 2, 3, or 4, wherein a plurality of vibrator elements constituting the vibrator group are arranged with regularity on the substrate. The micro vibrator according to claim 1, 2, 3, or 4, wherein the vibrator element is excited in a second harmonic vibration mode. The micro vibrator according to claim 5, wherein the vibrator element is excited in a second harmonic vibration mode. A semiconductor device comprising the micro vibrator according to claim 1. In a communication apparatus provided with a filter for limiting the bandwidth of a transmission signal and / or a reception signal,
A communication apparatus comprising the filter using the micro vibrator according to any one of claims 1 to 7 as the filter.

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