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74 Threads found on Frequen
Hi, This little crystal oscillator I have designed by trial and error, uses crystals or ceramic resonators to oscillate at HF. There ia a "hitten" capacitor formed by the internal capacitance of the gate-source of the FET. When I set the source trimmer at extreme ends (especially at low values, max OSC gain) the oscillator changes frequency by a f
used na to get the s parameters of the board and also took s1p files. now when i am using ads to plot those using these s1p files i am not seeing the same plots. just measured the s11 from na because so in simulation i am simply loading the s1p files and doing the s parameter simulation by simply keeping a terminal in the desired frequency.
An old fashioned inverter that produced a squarewave or modified "sinewave" used a huge iron core or toroid transformer. If you make one yourself then you would probably buy a few expensive transformers to find one that produces the correct output voltage that is not adjustable. A modern inverter produces a pure sinewave with high frequency PWM an
Hi! I designed a ferrite bead model and choose frequency domain solver. frequency range are between 0 ~20 GHz. When I ran it, my computer operated slowly and crashed last. How should I set up my simulation environment so that I can obtain Results from 0~20 GHz? Thanks for help!
I have never noticed hum in transmissions before, are you certain it is part of the transmission and not being introduced in your receiver? Tell us more: 1. is the hum low frequency (50/60/100/120 Hz for example?) 2. are you haering the hum on AM or FM stations or both? A high pass filter will block the hum but if it is modulating the audio itsel
A transistor has exponential transconductance. Then without any negative feedback when the signal level is low the output is fairly linear but at high levels it is extremely distorted even if it is not clipping. An opamp can have a wide frequency response at low output levels but at high output levels its slew rate limits its high frequencies.
Hello, I need to obtain some voltage levels below 5Volts from 5Volts power rail. I am thinking about to use PWM with 10Khz modulation frequency. For example with %50 duty cycle i am planing to get 2.5Volts. In order to this i am planing to use the circuit below. 121876 My load has resistive character. Thermoelect
For lowest jitter (phase noise) you need to have an oscillator that is tuned with a very high Q resonant circuit. Best would be a crystal or surface acoustic resonator for fixed frequency, or at the very least an LC resonant tank circuit if you need to vary the frequency. The amplifying device associated with the oscillator must also be of a low n
Hello, I am a refrigeration engineer. I have studied a bit about the DC inverter air conditioner that promises a lot of energy saving. What I understood is that they require BLDC motor based compressors and dedicated electronic circuitry for operation. I think the existing compressors in conventional split air conditioners can be used for var
Hi all, I am supposed to design simple microstrip patch antenna with 50Ω cpw feed in HFSS. I know cpw equations how to use these equations and calculate related dimensions. I also confirmed it with using some programs such as TXline and AppCAD however at the end I can't find reasonable return loss values at the desired center frequency. Then
108115 Hi,everyone,In this picture,we can see the PA circuit board.The input port has a balun with transformer (4:1) using a ferrite,and the output has the 4:1 coax cable transformer and the coax cable balun. The frequency is 50MHz to 75MHz. I have two question for your help, thank you very much. The first question is abou
Hi Whether you can use your existing VCO or not depends on its ability to be pulled by the PLL and its loop filter. If your oscillator is not meant to be tuned by a dc-voltage, then you should rather use the internal VCO of the HEF4046. On the pin SIG_IN you should connect your reference oscillator which should be very stable! The HEF4046 then g
Hi there! I have an assignment that goes as follows: Pulse compression by using a Linear FM signal 1) Consider a (real) Linear FM signal with a center frequency, f0= 1250 MHz, a bandwidth, B = 100 MHz, and a length, T = 0.15 ?s. - What is the required sampling frequency, fs? - Derive an
The following (attached) is a 250W full bridge smps as used by a huge Telco in a PSU. Spec is fsw=300khz, vin=48v, vout=26v,current mode, CCM , Np/Ns = 1 The main cout cap is C54 (68uF) and you can see it has resistor R37 (220mR) in series with it. Why is this resistor there.? Why would you want to decrease the ESR-Cout zero
For electronic circuits it is best to have a common ground, this is because if the grounds have different voltages on them, then if anything changes (external coax braid is earthed for instance) what happens to the amplifier is not known, will it oscillate, blow a fuse, suffer a change in frequency response. The only time separate earths are us
Hi How to find out the amplitude and duration of a sine wave of different amplitudes? Consider a voltage sag ie, a 50hz signal of amplitude less than the normal one.I have to find out the amplitude and duration at wich this disturbance occurs. I have read some articles which gives some information that we can extract time and frequency inform
Hi all, I'm simulating the NF af a down-conversion mixer using pss and pnoise. All the cadence tutorails say you should set the RF port to DC, and then, when you choose the reference sideband in the pnoise form, you should choose + or -1 so your input frequency is Flo. I don't understand this. Isn't the input frequency the Frf (...)
At what frequency? Frank
hey i am designing a high gain opamp with BJTS, using a bipolar supply.. cn anyone help me in wat stages i should divide ths in order to achieve the reqd output??? the input frequency is to b kept 100kHz and the open loop gain must, at least, be 100.. You mean the open loop gain must be 100 at a frequency of 100
I have 3 devices:- a printer/scanner, a multimeter and my granddaughter?s expensive calculator (that does everything except make coffee) that intermittently do not turn on when the on/off button is pressed. In the case of the printer/scanner, it is the scan button rather than the on/off button. They work well if turned on & off frequently, but