How do I generate a broadband or wideband carrier?

[lolone]

Generating a carrier on a single frequency is simple, just use an oscillator of a specific frequency and amplify.

But how do I generate a carrier that is 100KHz wide, or even 100MHz wide? The obvious answer is more oscillators, but is there a better way?

 

[berkeman]

Welcome to the PF.

I don't think there is such a thing as a "carrier that is 100kHz wide". You can fill out a 100kHz channel with multiple carriers (like in OOFDM), or you can modulate a carrier, but a single carrier is generally at a single frequency.

What is the context of your question? What are you studying?

 

[lolone]

I don't think there is such a thing as a "carrier that is 100kHz wide".

I understand this.

You can fill out a 100kHz channel with multiple carriers (like in OOFDM), or you can modulate a carrier, but a single carrier is generally at a single frequency.

My question is related to generation and independent control of multiple carriers spanning a given bandwidth (i.e. 100KHz or 100MHz.)

What is the context of your question? What are you studying?

I have been looking at some types of digital signals with large bandwidths (1/4/8MHz, etc). Is this bandwidth composed of independent carriers, or is it the result of interactions due to the modulation scheme employed?

 

[Redbelly98]

Thread locked pending moderation.

 

[alphysicist]

Generating a broadband or wideband carrier involves using multiple oscillators and combining their frequencies to create a wider frequency range. This can be achieved through techniques such as frequency mixing, where two oscillators with different frequencies are combined to create a new frequency that is the sum or difference of the original frequencies. This method can be repeated multiple times to generate a wider range of frequencies.

Another approach is to use a frequency synthesizer, which is a device that can generate a wide range of frequencies by combining multiple oscillators and using a control circuit to select and combine specific frequencies. This allows for precise control and flexibility in generating a broadband or wideband carrier.

In addition, techniques such as phase-locked loops (PLLs) and direct digital synthesis (DDS) can also be used to generate a wide range of frequencies by manipulating the phase and frequency of a single oscillator.

Overall, while using multiple oscillators may seem like the most straightforward solution, there are more advanced techniques and technologies available for generating a broadband or wideband carrier. It is important to consider factors such as frequency stability, accuracy, and control when choosing the best method for your specific application.