Frequency를 갖느냐에 따라 크기가 다르게 느껴진다. 이를 고려한 것이 Weighting Level이며 종류로는 A, B, C weighting 이 있다. A weighting은 55dB 이하에서, B weighting은 55-85dB 사이에서, C weighting은 85dB 이상에서 적절하다.
표 1 Sound level conversion table
octave band A weighting B weighting C weighting
31.5Hz -39.4 -17.1 -3.0
63Hz -26.2
Abstract- This paper presents an X-band voltagecontrolled
hairpin resonator oscillator using GaAs
MESFET varactor. To get wide tuning range, the
hairpin resonator is combined with the MESFET
varactor. It is incorporated into the series feedback
oscillator. The measurement of the oscillator
showed the frequency tuning range of 11.15 MHz
with the output power flatness less than 0.10 dB at
t
2.3 C-V graph
The measured MOS capacitance (called gate capacitance) varies with the applied gate voltage.
① Measurement of C-V characteristics
-Apply any DC bias, and superimpose a small (15 mV) ac signal
-Generally measured at 1 MHz (high frequency) or at variable frequencies between 1KHz to 1 MHz
-The dc bias VG is slowly varied to get quasi-continuous C-V characteristics
② C-V chara
4. Equipment
4.1 RCA cleaning
RCA cleaning is a series of rinsing procedure prior to experiment with Si wafer. The purpose of the RCA clean is to remove organic contaminants (such as dust particles, grease or silica gel) from the wafer surface. There are three steps to be performed. The first step is to remove organic contaminant from surface of wafer. Second step is to remove any oxide layer
DSB-TC 신호의 포락선은 인데 만일 라면 가 된다.
이면 변조된 신호의 포락선은 정보 신호 와 동일한 모양을 갖는다.
이 경우 수신기에서는 수신 신호의 포락선만 추출함으로써 를 복원할 수 있으며, 여기서 직류 성분만 제거하면 원 신호 을 복원할 수 있다. 이와 같은 포락선 검출기를 사용한 복조