Please check my spectrum analyzer idea (single conversion superheterodyne)

Please check my spectrum "analyzer" idea (single conversion superheterodyne)

I want to build simplest possible stand-alone spectrum "analyzer"/monitor (no USB, just few chips+LCD)
Requirements to precision, sweep speed, etc. are low. Just to see something, but it still can be useful!
Measuring frequencies in some range around 1..2.4 GHz.

I see two ways of doing that:

1) VCO + mixer + filter + logarithmic detector IC + DSP + LCD screen.
Rf is mixed with VCO ramped signal, filtered, provided to logarithmic detector IC, then DSP displays level on LCD screen using logarithmic detector IC data.
In this case i am not sure if we can talk about resolution bandwidth here. Can i use say 44kHz low-pass filter and a very-slow sweep time?

2) (preferred method). Use some tuner IC functionality, some tuner IC with integrated VCO, mixer, etc. Which IC can be used?

if you do not phase lock the VCO, your frequency will vary....maybe as much as 50-100 MHz, as the temperature ages or the VCO ages, or the battery droops.

You can use Analog Satellite Tuner to cover 950MHz-2150MHz band but these tuners are almost not produced anymore (obsolete). But the most difficult thing in this project will probably be calibration.Because frequency response overall system will not be flat as desired and a calibration has to be done for each small fraction-at least-of this band.These correction values should be inserted into DSP block to get a reasonable accuracy.
The tuner bandwidth can be extended by some tweaks..

One to 2.4 Ghz is a pretty fair fair frequency span.
And what sort of resolution bandwidth and sensitivity are you after ?
Building something pretty crappy may not be that difficult, but will it then be of any real practical use ?

I looked into all this myself some time back, and decided to buy a surplus 25 year old spectrum analyser (for only a few hundred dollars) that has a tracking generator, a vast number of features, excellent performance, and goes from 9Khz to 2.6 Ghz.

Can someone recommend an IC with integrated mixer and oscillator? I found some FM radio chips, I want to try at least smaller range, say below 1GHz. Kind of mixer with integrated oscillator (not Hittite ones, too expensive and too wide bandwidth for me).

Can I use MAX2120 somehow? https://datasheets.maximintegrated.com/en/ds/MAX2120.pdf

I do not know how tuners work exactly.
First, few GHz signal is moved down in frequency,
Then there is some tuner IC which move frequency further, down to TV set antenna input frequency range.

I want to find an IC which can provide this:
there is some signal, say 1239MHz
1) set internal VCO frequency to something like 1234 MHz
2) do mixing of input RF with this LO (VCO=1234 MHz)
3) provide IF output 1239-1234=5MHz
then i am going to use fast ADC to read IF output and perform FFT.
This way I can find frequency peak 5MHz. Knowing that VCO was 1234MHz i can calculate, that
frequency peak is probably 1234+5MHz or 1234-5MHz:
1239MHz or 1229MHz.

Providing different VCO frequencies scanning is could be performed.
Next step: i set VCO to 1235 MHz.
Result is 1239-1235 = 4MHz

Knowing VCO is 1235, and FFT peak is at 4MHz:
1235+4 = 1239
1235-4 = 1231

Using many scans i can see repeating pattern of 1239 MHz peak, so 1229 and 1231 are false reading and 1239 is true RF peak.

Can't edit my previous post:
an update:
I have learned about rtl sdr receiving, but i don't like the idea because of lack of documentation and USB port requirement.
I would like to have sound-card solution, so i can test it with PC, and then use simple DSP + LCD screen to make really small battery-powered spectrum indicator. Only indication is needed, error in peak around +-1mhz is ok too. Scanning speed can be slow too.

Currently i see such configuration:
1. adf4351 as signal source
2. some mixer (discrete, IC)
3. low-pass filter on the output of mixer, say 22kHz.

Then connect (3) output to sound card and perform FFT analysis, switching frequency sweep of adf351.

I do not need fast speeds. Just some slow scanning - spectrum indication.
So i can see the output of NRF24L01+ in continuous LO test mode for example.

I will happy to see some IC chip names for my task. I am wondering is there any narrowband receiving IC, which works in 100mhz...1GHz range, and can provide filtered IF of 22kHz (with frequency steps from 100mhz to 1GHz <=22kHz).