Adv Antest Corporation

Norio Arakawa

Takahiro Yamaguchi

Jun Miyajima

Yoshikazu Nakayama

Hiroyuki Konno

Hiromi Kosawa

Satoshi Umezu

Takayuki Ohgami

Toru Nakanishi

Yoshio Takanaga

The present invention provides a device authentication unit for authenticating a computer, a measuring device or another device having a serial number or another inherent device number. A software encrypting section receives a serial number and encrypts the received serial number in the public key method with the serial number being a public key. An encrypted data transmission section transmits the encrypted serial number. A received serial number decoding section receives an encrypted serial number and decodes the encrypted serial number using a secret key corresponding to the serial number. Public key decoding by the received serial number decoding section succeeds only if a correct serial number is given. Accurate serial number inherent to the device can be acquired and device authentication can be made.

Device authentication apparatus and method, and recorded medium on which device authentication program is recorded

A measuring device, a measuring device controller, a measuring system, a measurement process performing method and a recording medium thereof which can easily and adequately perform a measurement process are provided. The present invention is constructed to include a program receiving unitfor receiving a control program, which comprises contents prescribing a measurement process, from said network; a memorizing unitfor memorizing the control program; an initiating instruction receiving unitfor receiving a program initiating instruction of the control program from the network; and a measurement control unitfor letting a measuring unitperform the measurement process based on the control program memorized by the memorizing unitin case the initiating instruction receiving unitreceives the program initiating instruction.

Adapter for controlling a measuring device, a measuring device, a controller for a measuring device, a method for processing measurement and a recording medium

A network analyzer includes a raw data measuring portion for measuring an S parameter of a device under test, a measuring-system error-factor measuring portion for obtaining measuring-system error factors occurring in the measurement of the device under test, a parameter conversion factor calculating portion for obtaining a parameter conversion factor indicative of the relationship between impedance and measuring system error-factor-free data obtained by eliminating measuring-system error factors from the S parameter, an extended error-factor calculating portion for obtaining extended error factors by combining the measurement-system error factors and the parameter conversion factor, and a device-under-test calculating portion for obtaining the impedance from the S parameter and the extended error factors. Accordingly, the need for fixtures is eliminated and, further, the extended error factors are obtained in advance. Therefore, operation of the network analyzer can be simplified and the calculating speeds increased.

Network analyzer, network analytical method and recording medium

A high-speed discrete Fourier transform (DFT) apparatus utilizes a processor operating in parallel with data acquisition to calculate terms of a Fourier transform corresponding to the incoming data. Since the processor calculates the Fourier terms in real-time, overall transformation time is substantially reduced and is limited by only the data acquisition time. In another aspect, substantial reduction of the number of computations are achieved by transforming the plurality of terms in Fourier equations at the same time. In a further aspect, the high-speed DFT is advantageously applied to a network analyzer which obtains a transfer function of a device in a frequency domain and converts the transfer function to a time domain response to a simulated test signal.

High speed fourier transform apparatus

An analog input signal is converted into a digital signal. The digital signal is shifted to the difference frequency region by mixing it with each of a sine wave local signal and a cosine wave local signal to obtain complex waveform data. On the other hand, a trigger signal is generated when a reference signal meets a specific requirement, and a frame composed of a fixed number of data is defined which is synchronized with the trigger signal. The complex waveform data of each frame thus defined is phase rotated so that its phase angle has a predetermined value, or the phases of the local signals are synchronized with the trigger signal so that the complex waveform data of respective frames have the same phase. The in-phase complex waveform data of plural frames thus obtained may also be averaged, if necessary.

Digital lock-in amplifier

In an AD converting device in which an analog random noise is added by analog adding means to an analog signal to be converted and the added output is converted by an AD converter to a digital signal, an analog offset voltage, whose level variation is around (1 to 7) times the quantization step size .DELTA. of the AD converter, is generated by offset generating means and is also applied to the analog adding means. A random noise waveform is stored in a memory, the read-out output of which is converted by DA converting means to an analog random noise having an amplitude about (1/2 to 6).DELTA., and the converted output is used as the above-said random noise. A digital value of the offset voltage and the digital noise waveform are subtracted from the output of the AD converter, as required.

Growing community of inventors

Tokyo, Japan

Norio Arakawa