RF Workings of a Wifi Receiver

In summary: It is not uncommon to use inductors and capacitors on chip for filters and oscillators, particularly at higher frequencies. However, external components may still be necessary for certain applications and performance requirements. In summary, most RF receivers, including WiFi chips, use a network of oscillators, mixers, and filters to select a given frequency and remain insensitive to undesired signals. While some reactive components can be built on the chip itself, external components may still be necessary for certain applications.
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I am curious to know how the RF front end of a Wifi receiver works. From my understanding, most RF receivers have to use networks of various oscillators, mixers, and filters to select a given frequency and remain insensitive to undesired signals at different frequencies, and I suspect that WiFi is no different (although I could be wrong). However, Wifi chips are small and to my knowledge don't contain any elements usually used to implement oscillators and filters (like inductors and capacitors). So my question is, how are Wifi devices able to implement those systems? I guess this question doesn't apply specifically to Wifi, but any device that uses a integrated receiver system.
 
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  • #3
good response, mebigguy

and I just had to post that block diag here for ease of viewing ...

5367.gif
To the OP, so you can see that all the physically larger components caps and inductors are mounted on the circuit board outside of the chip
I can see at least 2 caps on the inside ( probably REALLY small values)

This is typical of a lot of LSI ( Large Scale Integration) chips for all sorts of transmitters and or receivers 2-waqy radios, TV/ FM Broadcast receivers
WiFi, Cellphones etc etc

Dave
 
  • #4
One reason I like arduino - all of the common shields are open source -- here is the complete schematic of the WiFi shield, so it shows the external components Davenn mentioned.
 
  • #5
You can buy (if you are an OEM) 2.4GHz wireless audio systems with the complete system (RF/PHY/MAC/ADC/DAC/AMP/Battery charger/USB, etc etc) on a single 3.3V chip. External capacitors and flash are about it for external components.
 
  • #6
Thanks for the info guys. I guess my question pertains specifically to what appear to be the variable filters on the diagrams. All filters I'm familiar with need some reactive component, like an inductor or capacitor. Is some technique used to build the reactive elements in the the chip itself, or does it use the external capacitors for this purpose. Or, is there a method of implementing such filters without the use of reactive components?
 
  • #7
Fischer777 said:
I guess my question pertains specifically to what appear to be the variable filters on the diagrams. All filters I'm familiar with need some reactive component, like an inductor or capacitor. Is some technique used to build the reactive elements in the the chip itself, or does it use the external capacitors for this purpose. Or, is there a method of implementing such filters without the use of reactive components?
That is just a block diagram that is shown above. It just shows the significant components, there are likely to be many more if you could see the full schematic diagram
 
  • #8
You can build inductors and capacitors on chip.
 

What is a Wifi receiver and how does it work?

A Wifi receiver is a device that allows electronic devices, such as smartphones and laptops, to connect to a wireless network. It works by receiving radio frequency (RF) signals from a Wifi router and converting them into digital data that can be used by the device.

What are the key components of a Wifi receiver?

The key components of a Wifi receiver include an antenna, an RF amplifier, a mixer, a local oscillator, a demodulator, and a digital signal processor. These components work together to receive and process the RF signals from the Wifi router.

How does the antenna in a Wifi receiver work?

The antenna in a Wifi receiver is responsible for receiving the RF signals from the Wifi router. It works by converting the electrical energy from the RF signals into radio waves that can be transmitted through the air. The size and shape of the antenna determine its ability to pick up and transmit these signals.

What is the role of the RF amplifier in a Wifi receiver?

The RF amplifier in a Wifi receiver is responsible for amplifying the weak RF signals received by the antenna. This is necessary because the signals weaken as they travel through the air. The RF amplifier boosts the signal strength, making it easier for the other components of the receiver to process the data.

How does the demodulator in a Wifi receiver work?

The demodulator in a Wifi receiver is responsible for decoding the RF signals into digital data that can be used by the device. It does this by separating the RF signals into their individual components, such as frequency and amplitude, and converting them into binary data that can be understood by the device.

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