摘要:
An object is to achieve reduction of a spurious in a delta-sigma type fraction division PLL synthesizer. In its configuration, first and second L-value accumulators 31 and 30 are provided. The difference between overflow signals 16 and 17 of the first and the second L-value accumulators 31 and 30 is acquired by an adder 29, so that in response to an output signal of the adder 29, a division ratio of a variable divider 2 having a division ratio switchable between M, M+1, and M−1 is switched. By virtue of this, the frequency of a spurious generated by operation noise of the first and the second L-value accumulators 31 and 30 is shifted to a frequency component higher than the prior art so that the spurious is removed by a loop filter (low pass filter) 5.
摘要:
A manufacturing method of a semiconductor device including an electrode having low contact resistivity to a nitride semiconductor is provided. The manufacturing method includes a carbon containing layer forming step of forming a carbon containing layer containing carbon on a nitride semiconductor layer, and a titanium containing layer forming step of forming a titanium containing layer containing titanium on the carbon containing layer. A complete solid solution Ti (C, N) layer of TiN and TiC is formed between the titanium containing layer and the nitride semiconductor layer. As a result, the titanium containing layer comes to be in ohmic contact with the nitride semiconductor layer throughout the border therebetween.
摘要:
A digital FLL/PLL is provided which is capable of converging an oscillation frequency from a VCO to a desired frequency at a high speed even without setting a damping factor corresponding to each VCO gain. A digital FLL/PLL of the present invention includes: a comparator for comparing a channel signal to a loopback signal having an oscillation frequency to generate a signal error; a digital loop filter for generating a control voltage that determines the oscillation frequency, on the basis of the signal error; a VCO for controlling an oscillation frequency on the basis of the control voltage; a loopback path through which the oscillation frequency generated by the VCO is outputted as the loopback signal to the comparator; and a control section for monitoring the signal error, and controlling the digital loop filter such that the oscillation frequency of the VCO becomes a stationary state, when detecting that the signal error meets a predetermined condition after the channel signal is switched.
摘要:
Provided is a transmitter including a polar modulation circuit which adjusts a timing lag between an amplitude component and a phase component more accurately than a conventional art. The polar modulation circuit includes: a first calculator for performing an exclusive OR logical operation between the amplitude component before and after being inputted to the first processing section; a second calculator for performing an exclusive OR logical operation between the phase component before and after being inputted to the second processing section; and a delay fluctuation detection/compensation section for obtaining a delay time of the amplitude component based on an amount of output accumulation of the first calculator; obtaining a delay time of the phase component based on an amount of output accumulation of the second calculator; detecting an amount of delay fluctuation by using the delay times; and adjusting timings of the amplitude component and the phase component.
摘要:
Provided is a transmitter including a polar modulation circuit which adjusts a timing lag between an amplitude component and a phase component more accurately than a conventional art. The polar modulation circuit includes: an extraction section for extracting an amplitude component and a phase component from an input signal; a first processing section for performing a first signal process on the amplitude component; a second processing section for performing a second signal processing on the phase component; an amplifier for synthesizing an output of the first processing section and an output of the second processing section and amplifying the synthesized outputs; a first calculator for performing an exclusive OR logical operation between the amplitude component before being inputted to the first processing section and the amplitude component after having been inputted to the first processing section; a first accumulation section for accumulating outputs of the first calculator; a second calculator for performing an exclusive OR logical operation between the phase component before being inputted to the second processing section and the phase component after having been inputted to the second processing section; a second accumulation section for accumulating outputs of the second calculator; and a delay fluctuation detection/compensation section for obtaining a delay time of the amplitude component based on an amount of accumulation of the first accumulation section; obtaining a delay time of the phase component based on an amount of accumulation of the second accumulation section; detecting an amount of delay fluctuation by using the delay times; and adjusting timings of the amplitude component and the phase component.
摘要:
A metallized ceramics substrate including: a ceramics body; a wiring pattern formed on one surface of the ceramics body; and a lead electrically-connected to the wiring pattern. The ceramics body has a through-hole, the lead penetrates the through-hole and sticks out from another surface of the ceramics body, and the lead is fixed by filling an electroconductive filler between the lead and the through-hole for keeping airtightness. The metallized ceramics substrate does not cause a problem of interlayer peeling and is excellent in airtightness and electric conductivity.
摘要:
A fabrication method for metallized a ceramics substrate including the steps of: forming a first conductive paste layer containing metallic powder on a sintered ceramics substrate; forming a second conductive paste layer containing metallic powder of which average particle diameter is different from that of metallic powder constituting the first conductive paste layer; and forming a first conductive layer and a second conductive paste layer. The surface roughness of the first conductive layer and the second conductive layer is different. By this method, it is possible to secure airtightness of the metallized ceramics substrate even if it is a multilayered substrate having a plurality of metallized layers.
摘要:
A semiconductor apparatus includes a signal source 7 that outputs a signal of predetermined frequency, a frequency divider 15 that receives the output signal of the signal source and is capable of switching the output signal to two or more frequency division ratios, a delta-sigma modulator 16 that controls the frequency division ratio of the frequency divider, and a bandpass filter 17 that receives an output of the frequency divider. The frequency of the input signal of the frequency divider is divided by the frequency division ratio controlled by the delta-sigma modulator, and quantization noise appearing in the output of the frequency divider generated by the delta-sigma modulator is attenuated with the bandpass filter. The semiconductor apparatus easily can convert a signal output by a single signal source to a signal of predetermined frequency and supply a plurality of signals of predetermined frequency using a simple configuration with reduced chip size.
摘要:
An insulating material high both in thermal conductivity and light reflectance, and a submount high in heat radiatability for mounting an LED element thereon, capable of raising a light utilization factor and quickly radiating heat generated from the element. For example, used as a substrate material of a submount is a nitride sintered body having a reflectance of light in the wavelength region of from 350 nm to 800 nm of 50% or more and a reflectance of light with a wavelength of 700 nm of 60% or more, obtained by sintering a preform consisting of a composition containing 100 parts by mass of aluminum nitride powder and 0.5 to 10 parts by mass of a compound containing an alkaline earth metal such as 3CaO×Al2O3 in an inert atmosphere containing a specific quantity of carbon vapor, or by burning a coat of a nitride paste applied on a base substrate having a heat resistance at a predetermined temperature.
摘要:
A fabrication method for metallized a ceramics substrate including the steps of: forming a first conductive paste layer containing metallic powder on a sintered ceramics substrate; forming a second conductive paste layer containing metallic powder of which average particle diameter is different from that of metallic powder constituting the first conductive paste layer; and forming a first conductive layer and a second conductive paste layer. The surface roughness of the first conductive layer and the second conductive layer is different. By this method, it is possible to secure airtightness of the metallized ceramics substrate even if it is a multilayered substrate having a plurality of metallized layers.