Software Radio (SR) is one of the most important emerging technologies for the
future of wireless communication services. By moving radio functionality into
software, it promises to give flexible radio systems that are multi-service, multi-
standard, multi-band, reconfigurable and reprogrammable by software.
Today’s radios are matched to a particular class of signals that are well defined
bytheircarrierfrequencies,modulationformatsandbandwidths.Aradiotransmitter
today can only up convert signals with well-defined bandwidths over defined center
frequencies, while, on the other side of the communication chain, a radio receiver
can only down convert well-defined signal bandwidths, transmitted over specified
carrier frequencies.
標(biāo)簽：
Software
Radio
上傳時(shí)間：
2020-06-01
上傳用戶：shancjb
本系統(tǒng)采用電動(dòng)機(jī)電樞供電回路串接采樣電阻的方式來(lái)實(shí)現(xiàn)對(duì)小型直流有刷電動(dòng)機(jī)的轉(zhuǎn)速測(cè)量。該系統(tǒng)主要由二階低通濾波電路,小信號(hào)放大電路、單片機(jī)測(cè)量顯示電路、開關(guān)穩(wěn)壓電源電路等組成。同時(shí)自制電機(jī)測(cè)速裝置,用高頻磁環(huán)作為載體,用線圈繞制磁環(huán),利用電磁感應(yīng)原理檢測(cè)電機(jī)運(yùn)行時(shí)的漏磁,將變化的磁場(chǎng)信號(hào)轉(zhuǎn)化為磁環(huán)上的感應(yīng)電流。用信號(hào)處理單元電路將微弱電信號(hào)轉(zhuǎn)化為脈沖信號(hào),送由單片機(jī)檢測(cè),從而達(dá)到準(zhǔn)確測(cè)量電機(jī)的速度的要求。In this system, the sampling resistance of armature power supply circuit is connected in series to measure the speed of small DC brush motor. The system is mainly composed of second-order low-pass filter circuit, small signal amplifier circuit, single-chip measurement and display circuit, switching regulated power supply circuit and so on. At the same time, the self-made motor speed measuring device uses high frequency magnetic ring as the carrier, coil winding magnetic ring, and electromagnetic induction principle to detect the leakage of magnetic field during the operation of the motor, which converts the changed magnetic field signal into the induced current on the magnetic ring. The weak electric signal is transformed into pulse signal by signal processing unit circuit, which is sent to single chip computer for detection, so as to meet the requirement of accurate measurement of motor speed.
標(biāo)簽：
直流電動(dòng)機(jī)
上傳時(shí)間：
2022-03-26
上傳用戶：
