Abstract: A voltage controlled oscillator includes an inductor circuit, C-coupling type variable capacitance circuits, a direct-coupling type variable capacitance circuit, and a negative resistance circuit, which are connected in parallel, and a reference voltage generating section that generates two reference voltages. A control voltage for feedback control of an oscillation frequency is applied to back gate terminals of variable capacitance elements of the variable capacitance circuits. The reference voltages are applied to gate terminals of the variable capacitance elements of the C-coupling type variable capacitance circuits, respectively.

Abstract: Provided is a PLL oscillation circuit that can reduce the variability of modulation sensitivity of a VCO 101 and obtain a desired output amplitude quickly with high precision. An amplitude detector 103 detects an output amplitude of the VCO 101. An amplitude controller 105 controls a current value of a variable current source 109 so as to have an output amplitude of the VCO 101 detected by the amplitude detector 103 to be a desired amplitude. A LPF 108 is connected between the amplitude controller 105 and the variable current source 109. A switch 107 connects or disconnects the LPF 108 between the amplitude controller 105 and the variable current source 109. The amplitude controller 105 is connected to the variable current source 109 through either the LPF 108 or the switching switch 107.

Abstract: A method for manufacturing a ceramic multi-layered substrate includes a first step of forming a green ceramic laminate including a plurality of stacked green ceramic base layers, a second step of firing the green ceramic laminate to sinter the green ceramic layers, and a third step of separating the sintered ceramic laminate formed by firing the green ceramic laminate into a ceramic multi-layered substrate. The green ceramic base layers stacked in the first step include a separation pattern formed along separation lines, the separation pattern disappearing during firing. In the third step, the sintered ceramic laminate is separated into a plurality of ceramic multi-layered substrates separated through a cavity formed by the disappearance of the separation pattern during the firing in the second step.

Abstract: Provided is a voltage-controlled oscillator that can hold an oscillation frequency at a desired value when an oscillation frequency changes due to the temperature, without narrowing a variable range of the oscillation frequency, and a PLL circuit, an FLL circuit, and a wireless communication device, which use the voltage-controlled oscillator. A control voltage Vt is applied to a connection point Y between variable capacitors 121 and 122 included in a variable capacitance circuit 120. A control signal Fse1 is applied to a switching element 132 included in a capacitance switching circuit 130. A power-supply voltage Vdd is applied by a control section 170 to a connection point X between inductors 111 and 112 included in an inductor circuit 110. A voltage value of the power-supply voltage Vdd is controlled such that the oscillation frequency of the local oscillation signal is held at a constant regardless of a temperature change.

Abstract: A voltage controlled oscillator includes first and second variable capacitance circuits 120 and 130, and first and second capacitance switch circuits 140 and 150. A control voltage Vt is fixedly applied to the first variable capacitance circuit 120, and control signals Fsel2 and Fsel3 are fixedly applied to the first and second capacitance switch circuits 140 and 150, respectively. In a case where both of the control signals Fsel2 and Fsel3 are at a low level, the control signal Fsel1 is applied to the second variable capacitance circuit 130. In the other cases, the control voltage Vt is applied to the second variable capacitance circuit 130. As a result of this control, a high-frequency variable range is divided into two variable ranges, one based on upper frequencies and the other based on lower frequencies. This enables suppression of a frequency sensitivity without narrowing the high-frequency variable range.

Abstract: A voltage controlled oscillator has a reference voltage generation section for generating a plurality of reference voltage based on a power supply voltage. Reference voltages Vref1, Vref2, and Vref3 are inputted to variable capacitance circuits A, B, and C, respectively. Reference voltages Vref1, Vref2, and Vref3 each has a fixed value, and a difference between the first reference voltage Vref1 and the second reference voltage Vref2 and a difference between the second reference voltage Vref2 and the third reference voltage Vref3 represent values different from each other. A control voltage Vt for feedback-controlling an oscillation frequency is inputted to each of the other of the terminals of the variable capacitance element of each of the n variable capacitance circuits such that the control voltage Vt having the same value is inputted to the each of the other of the terminals.

Abstract: Provided is a PLL oscillation circuit that can reduce the variability of modulation sensitivity of a VCO 101 and obtain a desired output amplitude quickly with high precision. An amplitude detector 103 detects an output amplitude of the VCO 101. An amplitude controller 105 controls a current value of a variable current source 109 so as to have an output amplitude of the VCO 101 detected by the amplitude detector 103 to be a desired amplitude. A LPF 108 is connected between the amplitude controller 105 and the variable current source 109. A switch 107 connects or disconnects the LPF 108 between the amplitude controller 105 and the variable current source 109. The amplitude controller 105 is connected to the variable current source 109 through either the LPF 108 or the switching switch 107.

Abstract: A voltage controlled oscillator of the present invention includes an inductor circuit 110, C-coupling type variable capacitance circuits 120 and 140, a direct-coupling type variable capacitance circuit 130, and a negative resistance circuit 160, which are connected in parallel, and a reference voltage generating section 180 that generates reference voltages Vref1 and Vref2. A control voltage Vt for feedback control of an oscillation frequency is applied to back gate terminals of variable capacitance elements 121, 122, 131, 132, 141, and 142 of the variable capacitance circuits 120, 130 and 140. The reference voltages Vref1 and Vref2 are applied to gate terminals of the variable capacitance elements 121, 122, 141, and 142 of the C-coupling type variable capacitance circuit 120 and 140, respectively.

Abstract: A voltage controlled oscillator including an inductor circuit including inductors 101, 102, a variable capacitance circuit 110 having variable capacitance elements 111, 112 changing a capacitance according to a voltage difference between two terminals thereof and having capacitive elements 113, 114 cutting a DC component, a negative resistance circuit including cross-coupled oscillating transistors 103, 104, and a time-switched level shift circuit 108 for shifting a reference voltage to two or more levels in a predetermined period. A connection point A of the variable capacitance elements is supplied with a control voltage Vt controlling an oscillation frequency, and connection points B, C of the variable capacitance elements and the capacitive elements are supplied with a reference voltage Vref output from the time-switched level shift circuit 108 via resistors 115, 116.

Abstract: A chip-mounted substrate includes a chip electronic component on a ceramic substrate having surface electrodes. The chip electronic component includes a ceramic sintered compact defining an element assembly and terminal electrodes. The surface electrodes of the ceramic substrate are integrated with the corresponding external terminal electrodes by sintering.

Abstract: A voltage controlled oscillator of the present invention comprises a reference voltage generation section 114 for generating a plurality of reference voltage based on a power supply voltage. A first to a third reference voltages Vref1, Vref2, and Vref3 are inputted to a first to a third variable capacitance circuits A, B, and C, respectively, at each one of terminals of each of the first to the third variable capacitance circuits A, B, and C. The first to the third reference voltages Vref1, Vref2, and Vref3 each has a fixed value, and a difference between the first reference voltage Vref1 and the second reference voltage Vref2 and a difference between the second reference voltage Vref2 and the third reference voltage Vref3 represent values different from each other.

Abstract: A method for accurately and easily manufacturing a ceramic multi-layered substrate includes a first step of forming a green ceramic laminate including a plurality of stacked green ceramic base layers, a second step of firing the green ceramic laminate to sinter the green ceramic layers, and a third step of separating the sintered ceramic laminate formed by firing the green ceramic laminate into a ceramic multi-layered substrate. The green ceramic base layers stacked in the first step include a separation pattern formed along separation lines, the separation pattern disappearing during firing. In the third step, the sintered ceramic laminate is separated into a plurality of ceramic multi-layered substrates separated through a cavity formed by the disappearance of the separation pattern during the firing in the second step.

Abstract: In a method for producing a multilayer ceramic substrate, a green ceramic laminate includes green conductive patterns arranged on a plurality of ceramic green sheets and portions to be formed into a plurality of multilayer ceramic substrates. Boundary-defining conductive patterns are arranged on the ceramic green sheets and along boundaries of the multilayer ceramic substrates. The boundary-defining conductive patterns have firing shrinkage characteristics that are different from those of the ceramic green sheets. During firing of the green ceramic laminate, cavities adjacent to edges of the boundary-defining conductive patterns are formed. A sintered ceramic laminate is divided at edges passing through the cavities.

Abstract: A voltage controlled oscillator 100 comprises an inductor circuit including inductors 101, 102; a variable capacitance circuit 110 which includes variable capacitance elements 111, 112 for changing a capacitance value in accordance with a voltage difference between both of two terminals thereof and capacitive elements 113, 114 for cutting a DC component, and which is connected in parallel to the inductor circuit; a negative resistance circuit including cross-coupled oscillating transistors 103, 104; and a time-switched level shift circuit 108 for shifting a reference voltage to be output to two or more levels in accordance with time. A connection point A of the variable capacitance elements is supplied with a control voltage Vt for controlling an oscillation frequency, and connection points B, C of the variable capacitance elements and the capacitive elements are supplied with a reference voltage Vref output from the time-switched level shift circuit 108 via resistors 115, 116.

Abstract: The present invention provides a differential voltage control oscillator including: a parallel resonance circuit in which an inductor circuit, a variable capacitance circuit, and a radio-frequency switching circuit are connected in parallel together; and a negative resistance circuit connected in parallel with the parallel resonance circuit.

Abstract: A plurality of control voltages V1 to V3 are sequentially applied to a VCO 5 so as to obtain, for each of these control voltages, the operating reference voltages Vref1 to Vref3 for the variable capacitor elements VC51 to VC56 with which the difference between the oscillation frequency of the VCO 5 and the target frequency is minimum. With this operation, the frequency synthesizer of the present invention can not only set the oscillation frequency of the VCO 5 for a single control voltage to a desirable value but also set the control sensitivity at the oscillation frequency of the VCO 5 with varied control voltage to a desirable value.

Abstract: An oxide porcelain composition includes at least one metal element selected from Al, Si, Ba, B and Cr. The oxide porcelain composition contains about 11.5 weight percent to 60.0 weight percent of Al, in the form of Al2O3; about 4.0 weight percent to 70.0 weight percent of Si, in the form of SiO2; about 4.0 weight percent to 40.0 weight percent of Ba, in the form of BaO; about 1.0 weight percent to 30.0 weight percent of B, in the form of B2O3; and about 0.3 weight percent to 3.0 weight percent of Cr, in the form of Cr2O3.

Abstract: A voltage controlled oscillator comprises a parallel resonance circuit including an inductor circuit, a variable capacitance circuit, and a high-frequency switch circuit, a negative resistance circuit and a frequency control section, and a frequency tuning sensitivity control section. The frequency control section shifts a band of an oscillation frequency by controlling ON/OFF of a switching element included in the high-frequency switch circuit. The frequency tuning sensitivity control section adjusts a change rate of a total capacitance of the variable capacitance circuit with respect to a control voltage, depending on a band to be used. The frequency tuning sensitivity control section is connected to a virtual ground point of a differential signal.

Abstract: An oxide porcelain composition includes at least one metal element selected from Al, Si, Ba, B and Cr. The oxide porcelain composition contains about 11.5 weight percent to 60.0 weight percent of Al, in the form of Al2O3; about 4.0 weight percent to 70.0 weight percent of Si, in the form of SiO2; about 4.0 weight percent to 40.0 weight percent of Ba, in the form of BaO; about 1.0 weight percent to 30.0 weight percent of B, in the form of B2O3; and about 0.3 weight percent to 3.0 weight percent of Cr, in the form of Cr2O3.

Abstract: A voltage controlled oscillator comprises a parallel resonance circuit including an inductor circuit, a variable capacitance circuit, and a high-frequency switch circuit, a negative resistance circuit and a frequency control section, and a frequency tuning sensitivity control section. The frequency control section shifts a band of an oscillation frequency by controlling ON/OFF of a switching element included in the high-frequency switch circuit. The frequency tuning sensitivity control section adjusts a change rate of a total capacitance of the variable capacitance circuit with respect to a control voltage, depending on a band to be used. The frequency tuning sensitivity control section is connected to a virtual ground point of a differential signal.