UAV drone antenna Frequency gain and length

Understanding the Relationship Between Antenna Frequency, Gain, and Length in Drones

Here is some example of omnidirectional antenna on frequency, gain and length.

Frequency	Gain	Length	Noted
433MHz	5dBi	Φ3.2*120cm
512-562MHz	6dBi	Φ1.4*140cm	spring
566-678MHz	1dBi	Φ1.3*28cm	gooseneck
566-678MHz	4dBi	Φ1.6*70cm	spring
566-803MHz	2/3dBi	Φ1.6*60cm	gooseneck
634-674MHz	6dBi	Φ2*1200cm	spring
703-803MHz	4.5dBi	Φ1.3*47cm	gooseneck
806-826MHz	2dBi	Φ3.8*25cm
806-826MHz	2dBi	Φ1.3*36cm	gooseneck
806-826MHz	4dBi	Φ1.6*55cm	spring
806-826MHz	5dBi	Φ2.2*60cm
840-845MHz	2dBi	Φ1.3*25cm
840-845MHz	7dBi	Φ3.2*150cm
902-928MHz	2dBi	Φ1*15cm
902-928MHz	2dBi	Φ1.3*17cm
902-928MHz	5dBi	Φ1.3*60cm
902-928MHz	9dBi	Φ2*120cm	Vertical Beamwidth 15°±3
902-928MHz	8dBi	Φ3.2*120cm	Vertical Beamwidth 20°±3
1340-1450MHz	2dBi	Φ1.3*16cm
1350-1450MHz	6dBi	Φ1.3*60cm	gooseneck
1350-1470MHz	6dBi	Φ2*60cm
1350-1470MHz	8dBi	Φ2.5*60cm
1370-1450MHz	5dBi	Φ1.6*50cm	spring
1370-1450MHz	6dBi	Φ1.6*60cm	spring
1420-1530MHz	2dBi	Φ1.3*25cm	gooseneck
1420-1530MHz	2dBi	Φ1*15cm
1420-1530MHz	2dBi	Φ1.3*12cm
1420-1530MHz	3dBi	Φ1.3*31cm	gooseneck
1420-1530MHz	3dBi	Φ1.6*20cm	spring
1420-1530MHz	4dBi	Φ1.3*37cm	gooseneck
1420-1530MHz	4dBi	Φ1.6*35cm	spring
1420-1530MHz	9dBi	Φ3.2*120cm
1420-1530MHz	10dBi	Φ5*120cm
2400-2500MHz	2dBi	Φ1.3*7.3cm
2400-2500MHz	2dBi	Φ1.3*16cm
2400-2500MHz	2dBi	Φ1.3*20cm
2400-2500MHz	4dBi	Φ1.3*25cm
2400-2500MHz	6dBi	Φ2*35cm
2400-2500MHz	8dBi	Φ2*60cm
2400-2500MHz	11dBi	Φ3.2*120cm
2400-2500MHz	12dBi	Φ2*120cm

1. Spring: means spring antenna, spring-loaded antenna, shock-absorbing antenna, shock-mounted antenna.
2. Gooseneck: means an antenna with a flexible gooseneck section that can be bent and positioned. flexible antenna, adjustable antenna. A flexible gooseneck antenna designed for adjustable positioning and durability.

Here is some example of flat panel directional antenna on frequency, gain and length.

Frequency	Gain	Size cm	Note
1350-1450MHz	14dBi	26*26*4.5	Horizontal beamwidth 35°±5 Vertical Beamwidth 35°±5
1350-1470MHz	12dBi	26*26*4.5	Horizontal beamwidth 65°±5 Vertical Beamwidth 30°±5
1350-1470MHz	12dBi	26*26*4.5	Dual-polarized (H+V) Horizontal beamwidth 65°±5 Vertical Beamwidth 30°±5
1350-1470MHz	14dBi	26*26*4.5	Dual-polarized (V+V) Horizontal beamwidth 35°±5 Vertical Beamwidth 35°±5
1370-1450MHz	16dBi	39*39*5.1	N-K
1370-1450MHz	16dBi	39*39*5.1	SMA-N-K-N-KW
1370-1450MHz	16dBi	39*39*5.1	Dual-polarized (±45°)
1370-1450MHz	16dBi	39*39.5.1	Dual-polarized (V+V)
2400-2500MHz	14dBi	22*22*2.5
2400-2500MHz	18dBi	30.5*30.5*2.5
2000-2500MHz	18dBi	39*39*5.1
5640-5760MHz	14dBi	19*19*25

Here is some example of blade antenna, knife-shaped antenna on frequency, gain and length.

Frequency	Gain	Length cm
566-678MHz	1dBi	9.2*4.2*16
566-678MHz	1dBi	11.6*8*15.5
840-845MHz	2dBi	9.2*4.2*16
840-845MHz	2dBi	11.6*8*15.5
1350-1470MHz	4dBi	9.2*4.2*32.5
1350-1470MHz	6dBi	9.2*4.2*48
1420-1530MHz	2dBi	2.7*2.4*12
1420-1530MHz	2dBi	11.6*8*15.5

When choosing antennas for drones, customers often ask three related questions:

• Why do antennas at different frequencies look so different?
• Why are some antennas longer and others very short?
• Does higher gain always mean better performance?

The answers all come down to the relationship between frequency, antenna length, and gain. Let’s break it down in a simple and practical way.

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1. Frequency Determines Antenna Size

Antenna design is governed by a basic rule of physics:

Higher frequency = shorter wavelength = shorter antenna

Every antenna works by interacting with radio waves. The physical length of an antenna is usually a fraction of the signal’s wavelength (commonly ¼ or ½ wavelength).

Typical Drone Frequencies and Antenna Lengths

Frequency Band	Wavelength	Typical Antenna Length
900 MHz	~33 cm	8–16 cm
1.2 GHz	~25 cm	6–12 cm
2.4 GHz	~12.5 cm	3–6 cm
5.8 GHz	~5.2 cm	1–3 cm

What this means for drones:
Higher-frequency systems allow much smaller antennas, which is why compact drones often use 2.4 GHz or 5.8 GHz.

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2. Antenna Length Influences Gain

Antenna gain does not amplify power. Instead, it describes how effectively the antenna focuses energy in certain directions.

In general:

Longer antennas (relative to wavelength) can achieve higher gain

For example, at the same frequency:

• A short antenna provides wide, uniform coverage
• A longer antenna concentrates energy more horizontally
• Concentrated energy = higher gain = longer communication range

Example at 2.4 GHz

Antenna Type	Length	Typical Gain
Short whip	~3 cm	1–2 dBi
Half-wave	~6 cm	2–3 dBi
Collinear	10–20 cm	5–8 dBi

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3. Higher Gain Comes With Trade-Offs

This is especially important for drones.

As antenna gain increases:

• The signal beam becomes narrower
• Vertical coverage is reduced
• Performance becomes more sensitive to drone orientation

In other words:

Higher gain increases range, but reduces tolerance to attitude changes

For drones that pitch, roll, and yaw frequently, extremely high-gain antennas are not always the best choice.

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4. How Frequency Affects Gain in a Fixed Space

On drones, antenna size is often limited by the airframe.

If antenna length is fixed:

• Higher frequency means the antenna is electrically longer
• This allows higher achievable gain within the same physical size

That’s why short antennas at 5.8 GHz can still offer respectable gain, while the same size antenna at 900 MHz would perform poorly.

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5. Practical Guidelines for Drone Applications

Control & Telemetry (Stability First)

• Frequency: 900 MHz or 2.4 GHz
• Antenna: short, low-gain (1–3 dBi)
• Benefit: robust link during maneuvering and attitude changes

Video Transmission & Long Range

• Frequency: 1.2 GHz or 5.8 GHz
• Antenna: longer or directional (5–10 dBi)
• Benefit: extended range when orientation is controlled

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6. Simple Takeaway

You can summarize the relationship like this:

Frequency sets the antenna size,
antenna size limits achievable gain,
and higher gain trades coverage for distance.

Understanding this balance helps ensure reliable drone communication and optimal performance in real-world flight conditions.