24 GHz transverter

My 24.048 GHz transverter is an easy and cheap solution with less Tx power. I use an old mixer design made by Michael DB6NT.
Only a few parts are needed. A 12 GHz module, harmonic-mixer module, IF transmitter/receiver and an antenna.

24 ghz transverter

Click on image, download and extract my Excel sheet "Link budget v2.1" to calculate microwave links up to 1000 GHz. Calculation of atmospheric attenuation (ITU-R P.676-12) is included.

microwave link budget

1. Offset dish and tripod with pan/tilt mount

Same design as for my 76 GHz transverter and pan/tilt head.

2. W2IMU dual mode feed horn

hdl_ant software by W1GHZ is a good choice to calculate a dual mode feed horn. It is a circular wave guide with a diameter of 10.1 mm and the aperture is 19.4 mm (depth of 30.6 mm).
Wave length = 12.5 mm
WR-42: 10.7 x 4.3 mm

24 ghz horn 24 ghz horn

3. Transverter

1st version: MK II transverter

I use this mixer design from the 90s of last century.
RX NF = 8 dB (DSB)
TX power max = 0.5 mW (SSB), 1.3 mW (DSB)
To get maximum TX output use short diode leads, mount both diodes "overhead" and flat on the PCB. I used flags between diodes and waveguide pin. I reached 0.85 mW (DSB).
Needed external reference power is approx. 25-60 mW (14-18 dBm) @ 12 GHz
11952 * 2 + 144 IF = 24048 MHz

24 ghz system

24 ghz system

24 ghz transverter

24 ghz transverter

NORT PLL with arduino, transceiver with dual mode horn:

24 ghz transverter

2nd version: MK III transverter

Again a DB6NT transverter with coax output. Size is only 44 x 24 mm and a I made a small aluminium housing 50 x 30 x 18 mm. Same performance as MK II.
Power consumption: 20 mA @12V

24 ghz transverter

24 ghz transverter

4. PLL with 11952 MHz output

1st solution:

I use a modified NORT PLL to obtain 11952 MHz for the transverter input. I removed the internal 20 MHz quartz and mounted a SMA connector which is an external reference input now.
See more under electronics.
Output power : 13 dBm


ADF4153 parameters for reference frequency of 20 MHz. VCO output is 2988 MHz and this gives 2988 *4 = 11952 MHz for our mixer.


I prefer 23.715 MHz as reference frequency. The reason is that I use output B (locked to output A) of my GPSDO for my 76 GHz transverter and output A for my 24 GHz transverter.


2nd solution:

LO/2 power could be higher to get more power for the mixer and 24 GHz output. I built a 12 GHz LO module designed by DB6NT.
11.952 GHz ouput: 70 mW (18.5 dBm)
Current consumption @12V: 220 mA

12 ghz oscillator

5. New system with preamplifier, power amplifier and cavity filter

DB6NT preamplifier:

Noise figure: ~2 dB
Gain: 24 dB
Current consumption: 60 mA

24 ghz preamplifier LNA

Power amplifier module:

I got this modified Ceragon REMEC ED-0416 PA module from OE2JOM. Gain is extremely high and therefore a low cost/performance transverter with low output power is sufficient.
Gain: ~50 dB
Output power: ~1.5 W

24 ghz power amplifier

OE9PMJ cavity filter:

I got this used cavity filter from OE5VRL.

24 ghz OE9PMJ cavity filter

Assembled system:

6. GPS disciplined reference oscillator to set PLL reference input

Here I use a nice unit by Leo Bodnar. It has 2 separate outputs (3.3V CMOS level) from 450 Hz to 800 MHz and it uses GPS reveiver for very stable output frequency.
Output power up to 13.7 dBm
Current consumption @ 12V DC: 190 mA

GPS reference

7. IF receiver/transmitter

Therefore I use the good, old FT-290R.


8. Accu Pack

I use a 12V LiFePO4 accu with 10Ah because of its light weight, only 1.4 kg.

9. Test results

8th of November 2019: First successful 24 GHz (SSB, FM) test QSO.