Mixer Spur Chart Calculator

Calculate spurious products f = |m·f_LO ± n·f_RF| and identify spurs that fall in the IF band.

What are Mixer Spurs?

A mixer combines two radio frequencies — like mixing paint colors. But mixing creates not just the frequency you want, but dozens of unwanted "speckle" frequencies too. These are called spurs or spurious products, and they can land right on top of signals you're trying to receive.

Why it matters: Radio designers use spur charts to choose LO and RF frequencies that push all the unwanted mixing products away from the desired output. Getting this wrong means a receiver that hears ghost signals instead of real ones.

Mixer Parameters

Enter LO, RF, and IF frequencies in MHz.

LO Frequency (MHz)

The local oscillator — an internal reference signal used to shift the RF signal to the IF frequency

RF Frequency (MHz)

The incoming signal frequency you want to receive or process

IF Frequency (MHz)

The intermediate frequency output — usually RF minus LO. Spurs landing here cause interference

IF Bandwidth (MHz)

How wide the IF filter window is — spurs within this window (red cells) are problematic

Max Harmonic Order5

In-Band Spurs

IF window: 95.0 – 105.0 MHz

1×LO − 1×RF100.00 MHz

Spur Grid (m·LO + n·RF)

Rows = LO order (m), Columns = RF order (n). Red cells fall in the IF band.

m\n	n=0	n=1	n=2	n=3	n=4	n=5
m=0	—	1100.0	2200.0	3300.0	4400.0	5500.0
m=1	1000.0	2100.0	3200.0	4300.0	5400.0	6500.0
m=2	2000.0	3100.0	4200.0	5300.0	6400.0	7500.0
m=3	3000.0	4100.0	5200.0	6300.0	7400.0	8500.0
m=4	4000.0	5100.0	6200.0	7300.0	8400.0	9500.0
m=5	5000.0	6100.0	7200.0	8300.0	9400.0	10500.0

Frequencies in MHz. Highlighted cell (m=1, n=1) is the desired IF product.

All Spur Products

Sorted by frequency. 70 total products for order ≤ 5.

Product	Frequency (MHz)	In Band
1×LO − 1×RF	100.000
2×LO − 2×RF	200.000	—
3×LO − 3×RF	300.000	—
4×LO − 4×RF	400.000	—
5×LO − 5×RF	500.000	—
5×LO − 4×RF	600.000	—
4×LO − 3×RF	700.000	—
3×LO − 2×RF	800.000	—
2×LO − 1×RF	900.000	—
1×LO + 0×RF	1000.000	—
1×LO − 0×RF	1000.000	—
0×LO + 1×RF	1100.000	—
0×LO − 1×RF	1100.000	—
1×LO − 2×RF	1200.000	—
2×LO − 3×RF	1300.000	—
3×LO − 4×RF	1400.000	—
4×LO − 5×RF	1500.000	—
5×LO − 3×RF	1700.000	—
4×LO − 2×RF	1800.000	—
3×LO − 1×RF	1900.000	—
2×LO + 0×RF	2000.000	—
2×LO − 0×RF	2000.000	—
1×LO + 1×RF	2100.000	—
0×LO + 2×RF	2200.000	—
0×LO − 2×RF	2200.000	—
1×LO − 3×RF	2300.000	—
2×LO − 4×RF	2400.000	—
3×LO − 5×RF	2500.000	—
5×LO − 2×RF	2800.000	—
4×LO − 1×RF	2900.000	—
3×LO + 0×RF	3000.000	—
3×LO − 0×RF	3000.000	—
2×LO + 1×RF	3100.000	—
1×LO + 2×RF	3200.000	—
0×LO + 3×RF	3300.000	—
0×LO − 3×RF	3300.000	—
1×LO − 4×RF	3400.000	—
2×LO − 5×RF	3500.000	—
5×LO − 1×RF	3900.000	—
4×LO + 0×RF	4000.000	—
4×LO − 0×RF	4000.000	—
3×LO + 1×RF	4100.000	—
2×LO + 2×RF	4200.000	—
1×LO + 3×RF	4300.000	—
0×LO + 4×RF	4400.000	—
0×LO − 4×RF	4400.000	—
1×LO − 5×RF	4500.000	—
5×LO + 0×RF	5000.000	—
5×LO − 0×RF	5000.000	—
4×LO + 1×RF	5100.000	—
3×LO + 2×RF	5200.000	—
2×LO + 3×RF	5300.000	—
1×LO + 4×RF	5400.000	—
0×LO + 5×RF	5500.000	—
0×LO − 5×RF	5500.000	—
5×LO + 1×RF	6100.000	—
4×LO + 2×RF	6200.000	—
3×LO + 3×RF	6300.000	—
2×LO + 4×RF	6400.000	—
1×LO + 5×RF	6500.000	—
5×LO + 2×RF	7200.000	—
4×LO + 3×RF	7300.000	—
3×LO + 4×RF	7400.000	—
2×LO + 5×RF	7500.000	—
5×LO + 3×RF	8300.000	—
4×LO + 4×RF	8400.000	—
3×LO + 5×RF	8500.000	—
5×LO + 4×RF	9400.000	—
4×LO + 5×RF	9500.000	—
5×LO + 5×RF	10500.000	—

Mixer Spur Chart Calculator

Show the math