Basics of Control Impedance
With signal switching frequencies getting higher these days, impedance within tracks of Printed Circuit Boards has become an issue for modern day PCB designers. We can view PCB tracks as transmission lines since modern digital circuits operate at high clock frequencies and small signal switching periods.
Controlled Impedance:
The connector which feeds an incoming signal to a television set or wireless equipment is a frequently seen specimen of controlled impedance. The cable coming from an Aerial antenna can be a coaxial cable with low loss or more commonly a “flat twin” type of cable that comes with VHF receivers. The material from which cable is made and its length as well as width determine the feeder impedance.
It is easy to imagine PCB tracks as very precise, short wires connecting different components on a PCB. Just like the inner cable of a coaxial cable, PCB tracks carry the signal and are insulated from the ground which is the return path by PCB material. PCB material insulates the tracks from ground which can be compared with the way inner signal carrying cable of a coaxial cable is insulated from its return path.
Purpose of Controlling Impedance:
According to rules governing RF transmission, input impedance of the aerial has to be matched with impedance at receiving side and signal feeder thus transferring all available power to ensure strength and integrity of the RF signal. To make it more clear, an RF signal in ideal conditions needs a path having similar impedance from feeder to receiver.
Reflection of a signal towards its source diminishes signal strength, this happens when signal source and received are not matched and only a fraction of signal goes through. For high frequency transmissions, it becomes important for designers to ensure similar inductance, capacitance and other characteristics of a cable because it’s a signal path and not a simple conductor anymore. When these characteristics are strictly kept in check and cables are designed accordingly, they are called transmission lines.
Keywords:
SMT Reflow Oven, Lead free Reflow Oven, Reflow Oven Manufacturer, LED reflow oven, PCB Reflow Oven, Nitrogen Reflow Oven, Dual Rail Reflow Oven, China Reflow Oven, wave soldering machine, Dual Rail Wave Soldering Machine, Nitrogen Wave Soldering Machine, Wave Soldering Machine Manufacturer.
Flason Electronic Co.,ltd provide a full SMT assembly line solutions, including
SMT Reflow Oven,
Wave Soldering Machine,
Pick and Place Machine,
SMT Stencil Printer,
SMT AOI SPI Machine,
SMT Reflow Oven,
SMT Peripheral Equipment,
SMT Assembly line,
SMT Spare Parts
etc any kind SMT machines you may need, please contact us for more information:
wechat whatsapp:+8613691605420, Skype: flasonsmt, Email: sales@flason-smt.com |
 |
 |
 |
FAQ
1) This is the first time I use this kind of machine, is it easy to operate?
There is English manual or guide video that show you how to use machine.
If you still have any question, please contact us by e-mail / skype/ phone /trademanager online service.
2) If machine have any problem after I receive it, how can I do ?
Free parts send to you in machine warranty period.
If the part is less than 0.5KG, we pay the postage.
If it exceeds 0.5KG, you need to pay the postage.
3) MOQ ?
1 set machine, mixed order is also welcomed.
4) How can I buy this machine from you? ( Very easy and flexible !)
A. Consult us about this product on line or by e-mail.
B. Negotiate and confirm the final price , shipping , payment methods and other terms.
C. Send you the proforma invoice and confirm your order.
D. Make the payment according to the method put on proforma invoice.
E. We prepare for your order in terms of the proforma invoice after confirming your full payment.
And 100% quality check before shipping.
F.Send your order by air or by sea.
5)Why choose us ?
A. Gold supplier on Alibaba !
B. Trade assurance to US$54,000 !
C. Best price & Best shipping & Best service ! |
 |
