how to transmitt and receive one bit by up at 1GHz?

Dear All,

I am working on long range(~300m) transmitter and receiver design. Due to the chip limited(the lowest data rate = 4kbps), I would like to use microprocessor's general I/O to send one bit per second(low data rate) on antenna at 1GHz by load modulation(switch MOSFET). I am not sure whether it work or not. Please give me some advice? Is there any other solution suit low data rate to reach long range?

From receiver side, is there any simple circuit(input to microprocessor) to detect this bit per second(low data rate)? I am not sure it is possible or not. Is there any useful link or information about it?

Best Regards,

jerry

Use Morse code.

Dear vfone,

Thank you for your advice.

Is Morse code like AM modulation? Is there any useful link or information for the Morse code circuit design on trasmitter and receiver by microprocessor at 1GHz?

Best Regard,

jerry

check for ASK transceivers.

Dear kspalla,

Thank you for your advice.

I found a ask modulation diagram as attached file(13.56MHz could be 1GHz).

Microprocessor's general i/o could provide data("1"/"0"), but how could l get 1GHz carrier to mix with data. From transmitter side, does it need a oscillator generate 1GHz carrier? How could I design a mixer to combine 1GHz carrier and data ? From receiver side, could the data be converted from ask modulation signal with 1GHz carrier by a envelop detector? Is there any other simple way?

Is there useful link or information about simple circuit of ASK transmitter and receiver by microprocessor at 1GHz?

Best Regard,

jerry

Of course you have to multiply 2 signals with mixer.You have to use oscillator to create 1GHz sinusoidal carrier.From receiver side there are 2 options. The first one is coherent detection and the other is non-coherent detection. For Coherent detection you have to generate the same sinusoidal carrier.To do this you have to use PLL for synchronization.For Noncoherent detection simply use envelope detector to detect your signal.

Dear alpuslu,

Thank you for your advice.

From transmitter side, what kind of oscillator is easy to build for creating 1GHz sinusoidal carrier? Can I use the component (http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=744-1291-ND)($56.66 is quite expensive) to be oscillator? About the mixer, what kind of component could do this? Could the mixer be made by the component (http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=568-2372-1-ND)($4 is a little bit expensive) or transistor(BJT/MOSFET/JFET)?
Is there any useful link or informaiton about oscillator and mixer circuit design for 1GHz?

From the receiver side, the non-coherent detection might cheaper than coherent detection. How could I build a non-coherent detection by envolope detector, then input to microprocessor?
Is there any useful link or informaiton about envolope detector circuit design for 1GHz?

Best Regard,

jerry

Hi jerry

You should read books that are related with RF/Microwave Design for designing oscillator and mixer etc.You can use negative resistance oscillator for 1GHz sinusoidal carrier.For mixer there are so many alternatives as oscillators.You can use diode mixer if conversation gain is not important for you or FET mixer for conversation gain.As you said non-coherent detection is cheaper than coherent detection but non-coherent detection has some problems such as detecting error.

Kind Regards
ALP

Some points sound confused. "Load modulation" e.g. is a specific technique involved with inductively coupled passive RFID tags,
also Figure 6.12 is about this. I can't imagine a relation to a wireless 300 m link at 1 GHz

Dear alpuslu,

Thank you for your advice.

Would you recommand books about designing oscillator and mixer?
From your advice, I will search on:
1. negative resistance oscillator for 1GHz sinusoidal carrier for oscillator
2. diode mixer(don't care conversation gain) or FET mixer(consider conversation gain)

What does detecting error mean of non-coherent detection? Does it mean that if noise figure is too high and higher than threshold(Vt) of comparator(which connect to the output of envelope detector), will give fault output to microprocessor?

Best Regards,

jerry