Yozan Corporation

Sharp Kabushiki Kaisha Corporation

Sumitomo Metal Industries, Inc.

Kazunori Motohashi

Guoliang Shou

Makoto Yamamoto

Sunao Takatori

Changming Zhou

Toshiyuki Matsumoto

Yoshihiro Hirota

Takashi Tomatsu

Gouliang Shou

Shengmin Lin

Muneo Harada

Xuping Zhou

Kunihiko Suzuki

Jie Chen

Ying Chen

Xiaoling Qin

Takahiko Ooasa

Jian Luo

Guoliano Shou

Xiaoling Oin

In one aspect, the present invention provides a low power consumption matched filter. The signal received at an input terminal is input to a shift register having stages equal to the spread code length number after conversion into digital signals in an A/D converter. The outputs of the shift register stages are input to XOR circuits set corresponding to each stage, so that XOR operations are performed between the outputs and corresponding spread code bits d,to d,. The outputs of the XOR circuits are analogously added in an analog adder and output from an output terminal. In another aspect, a filter circuit uses an analog operation circuit to prevent lowered operational accuracy caused by residual charge. Input analog signals successively undergo sampling and holding in sample-and-hold circuits, are multiplied by coefficients stored in a shift register by multiplication circuits, and added in an addition circuit. Sample data transmission error storage is prevented by shifting coefficients in the shift register. Sample-and-hold circuits and multiplication circuits are formed by analog operation circuits, and each include a switch for canceling the residual charge. The sample-and-hold circuits and multiplication circuits normally working are refreshed sequentially by providing circuits for replacing their function. The addition circuit is refreshed in the same way.

Matched filter for spread spectrum communication systems and hybrid analog-digital transversal filter

A computational circuit for a multi-value addition comprising a parallel adder, an output adder, a quantizing portion and a logic conversion portion. Addition circuits in the above adders and thresholding circuits in the above quantizing portion consist of voltage-driven circuits including capacitive couplings.

Computational circuit

A small sensor circuit with reducible electric power consumption is formed by connecting inverting amplifiers comprised of CMOS inverters connected in an odd number of stages, in series to guarantee the linearity of the relationship between inputs and outputs, and connecting an impedance as a sensor between the inputs and outputs, or to an input.

Sensor circuit

A highly accurate vector absolute-value calculation circuit uses analog processing and minimal hardware. Signal voltages corresponding to an I component (real number part) and a Q component (imaginary number part) are input to a first absolute-value calculation circuit 13 and a second absolute-value calculation circuit 14 through terminals 11 and 12, respectively, and they are each converted into absolute-value signals. The component I absolute-value and component Q absolute-value are compared in a comparison circuit 20. According to the result, the larger absolute-value signals are output to an input capacitor 23 of a neural computation circuit, and the smaller absolute-value signals are output to an input capacitor 24 by controlling multiplexers 21 and 22. The capacity ratio of a feedback capacitor 26 of a neural computation circuit and input capacitors 23 and 24 is 11:10:5. The complex number absolute-value calculated by the following formula is output from an output terminal 27. ##EQU1##

Vector absolute--value calculation circuit

An stable inverted amplifying circuit includes an odd number of CMOS inverters and a feedback capacitance. Balancing resistances decrease the inverter open gain and limit the gain of the entire circuit. Serial capacitances act to prevent low-frequency oscillation. Oscillation-preventing circuits are also provided to reduce high-frequency oscillation. Sleep, refresh, and sleep-refresh switches are used to cancel residual loads and reduce power consumption.

Inverted amplifying circuit

A MOS inverter within a large scale integrated circuit (LSI) includes a pair of circuits with the same performance. Each of the circuits includes a plurality of MOS inverters serially connected from the first stage to the last stage. Each of the MOS inverters is provided with an input such that the input of the MOS inverters of the first stage are formed to be adjacent one another.

MOS inverter circuit

A multiplication and addition circuit multiplies each of a plurality of analog voltages by a corresponding digital multiplier and then adds up the products. First, each bit corresponding to each of the multipliers is multiplied with the corresponding analog voltage. Then, the products for each bit of the multiplier are added. The results are weighted by each bit weight and the weighted values are added. The multipliers are rotated so that there is the number of data transmission errors is lowered.

Multiplication and addition circuit

The present invention reduces parasitic capacitance in a capacitive element distribution system by running unit electrode lead lines and common electrode lead lines in different directions so that the conductor lines may be sufficiently separated to suppress parasitic capacitance.

Layout structure of capacitive element(s) and interconnections in a

An object of the present invention is to provide a matched filter circuit of small size and consuming low electric power. Paying attention that a spreading code is a 1 bit data string, an input signal is sampled and held as an analog signal along the time sequence, classified into '1' and '-1' and the classified signals are added in parallel by capacitive coupling in a matched filter circuit according to the present invention.

Matched filter circuit

Multiplication is performed including accumulation at high speed by a small quantity of hardware. Analog voltage X.sub.i corresponding to each element of the first input data string is input to capacitance switching circuits 10.sub.1 to 10.sub.n through input terminals 1.sub.1 to 1.sub.n. m bit of digital control data A.sub.i corresponding to each element of the second input data string are input to each capacitance switching circuit 10.sub.i, and each bit a.sub.j of the control signal A.sub.j is input to the corresponding multiplexer circuit 6.sub.ij. In the multiplexer circuit 6.sub.ij, the capacitances C.sub.ij corresponding to the value of each bit of the control signal a.sub.j are connected to the input terminal 1.sub.i or the reference charge V.sub.STD. The voltages corresponding to the products of inputted analog voltages X.sub.1 and the control signals A.sub.i are outputted from each capacitance switching circuit 10.sub.j. The output voltages of each capacitance switching circuit 10.sub.i are parallelly inputted to the operational amplifier 3 connected by a feedback capacitance Cf, and the sum of the input voltages is outputted from the operational amplifier 3. On the other hand, in order to provide a multiplication circuit of high calculation speed without deteriorating the calculation accuracy and circuit density, a multiplication circuit according to the present invention has a MOS switch or MOS multiplexer the MOS of which has a gate with width and length so that a time constant defined by the input capacitance and the switch etc. is constant.

Multiplication circuit

The present invention provides a weighted addition circuit for sampling, holding and performing weighted addition by a circuit smaller than a conventional one. In the weighted addition circuit of to the present invention, a capacitive coupling is connected to a plurality of switches which are further connected only to an input voltage. A voltage is held and a weight is added in the capacitive coupling.

Weight addition circuit

MOS inverter forming method within a large scale integrated circuit (LSI) for providing a pair of circuits with the same performance each of which comprise a plurality of MOS inverters serially connected from the first stage to the last stage, each the MOS inverters being provided with an input, characterized in that, the input of the MOS inverters of the first stage are adjacently positioned with facing to each other.

MOS inverter forming method

An A/D converting circuit for realizing a stable performance without being influenced by variations in characteristic values of each inverter. The A/D converting circuit includes a quantizing inverter which is constructed by a number of unit inverters parallelly connected.

A/D converting circuit with quantizers and inverted amplifiers

A multiplication circuit has two capacitive couplings connected first and second inverting amplifiers, respectively. Two steps of multiplication are performed by this circuit. Input is multiplied by a multiplier of a product of multipliers of the successive multiplication circuits, so the total multiplier can be rather large with similar capacitances to that of the conventional circuit.

An A/D converter including a first inverter having a linear characteristic and receiving an analog input voltage, a first quantizing circuit for quantizing the analog input voltage, a capacitive coupling to which an output of the first inverter and the first quantizing circuit are inputted, a second inverter receiving an output of the capacitive coupling and having the same characteristic of the first inverter, and a second quantizing circuit for receiving and quantizing an output of the second inverter. The A/D converter performs successive steps of quantizing/digitizing so as to achieve A/D conversion.

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Tokyo, Japan

Kazunori Motohashi