What Is the Difference Between LF, HF, And UHF Frequency?

RFID technology sends data between an RFID tag and a reader via radio waves. The frequency of the tag determines its read distance and thus its functionality.

RFID devices use three primary frequencies: Low Frequency (LF), High Frequency (HF), and Ultra High Frequency (UHF) (UHF).

But what's the distinction between these frequencies?

When used with RFID devices, the three frequencies behave differently. As a result, you should select a tag with the appropriate frequency to carry out your desired functions.

This article lists the features, benefits, and drawbacks of each frequency for your consideration.

What Is Frequency?

The number of waves that pass through a fixed object in a given time is referred to as its frequency. For example, if a wave takes 0.5 seconds to pass through an object, the frequency will be two waves per second.

The higher the frequency, the more waves pass through that specific object in a given time (usually per second).

Frequency is measured in Hertz (Hz), where one Hz equals one wave. Because many waves pass through objects per second, the unit is further classified as follows:

Kilohertz (kHz). This stands for one thousand hertz Megahertz (MHz). This unit represents one million hertz Gigahertz (GHz). The unit is one billion hertz Terahertz (THz). 1 trillion hertz

A typical radio spectrum ranges from 3 kilohertz to 3000 gigahertz.

The frequency of any RFID device will affect its functionality.

For instance,

A low-frequency tag has a read range of approximately 10 cm, whereas an ultra-high frequency tag has a read range of up to 100 meters.

What Is Low Frequency? Definition and Synopsis

Low frequency denotes that there are fewer waves passing through an object than high frequency.

Its frequency ranges from 125 to 134 kHz.

When using an LF device, this range means that approximately 125,000 to 134,000 waves pass through the object every second.

Low Frequency Advantages

The frequency ranges from 30 kHz to 300 kHz. However, the best operating frequency is 125 kHz.

Have a short read range of up to 10 cm

There is little chance of radio wave interference.

Slower reading speed

Longer wavelengths

Benefits of Low Frequency

They have longer wavelengths, making it easier for them to penetrate metallic objects. This feature allows the tags to work best with metallic objects.

It has a lower risk of radio wave interference. This feature allows you to use the LF tags in a highly electromagnetic environment.

It works best on liquid surfaces.

The Drawbacks of Low Frequency

Slow data transfer rates If you want a system that can read multiple tags at the same time, you cannot use these tags.

Reading range is limited. The LF tag must be no more than 10 centimeters away from your reader for data to be captured. This feature is severely limited because the technology cannot be used to track distant assets.

High Frequency: Definition

The high-frequency band encompasses all frequencies between 3 and 30 MHz. RFID HF systems, on the other hand, operate at a standard frequency of 13.56 MHz.

When compared to the LF, the frequency has a more extensive read range. As a result, HF tags are ideal for tracking items up to one meter away from the reader.

What Are the Advantages of High Frequency?

The band spans frequencies ranging from 3 to 30 MHz.

Have a reading range of 10 cm to 1 meter.

They are moderately sensitive to interference from other radio waves.

Can be used in ticketing and contactless payment systems.

Benefits of High Frequency

They can work in a moist environment.

Data transfer rates are relatively fast when compared to the LF.

Several HF standards apply, including ISO 15693 for object tracking and ISO/IEC 14443A and ISO/IEC 14443 for MIFARE use.

A greater read range of up to 1 meter.

More affordable than LF tags.

High Frequency Flaws

Not ideal when you need a reader to read multiple tags at the same time, but better than LF.

There is a moderate risk of radio-wave interference.

What Is Ultra-High Frequency?

The ultra-high frequency band encompasses all frequencies between 300 MHz and 3 GHz. It has a read range of up to 12 meters. Most UHF systems operate between 900 and 915 MHz. This frequency is typically used in toll payment and parking system management.

Characteristics of Ultra-High Frequency

Has a reading range of up to 40 feet/ 12 meters.

The lowest price on the market

Conforms to the UHF Gen2 standard (ISO 18000-63)

RFID segment with the fastest growth

UHF Advantages

cheaper than both HF and LF

The tags have a read range of up to 12 meters.

When compared to LF and HF, has the fastest data transfer rate.

UHF's Disadvantages

The most sensitive frequency. It is susceptible to radio frequency interference.

Does not work on metallic or liquid surfaces.

What Is the Difference Between Low Frequency, High Frequency, and Ultra High Frequency?

To transmit data, all of these frequencies employ radio waves. However, the number of waves that pass through objects varies greatly.

These distinctions affect their features and functionality. Low-frequency tags, for example, have fewer but longer wavelengths that are ideal for use with metallic and liquid objects. The long wavelength allows it to easily penetrate metallic objects. On the downside, these tags will only have a 10 cm read range.

Because of these characteristics, LF tags are ideal for use when:

Tracking fruits, vegetables, beverages, and other high-water-content substances

Tagging of animals

Controlled access (can be used with access cards due to their limited read range)

The read range of high-frequency tags is up to one meter. As a result, you should use these tags when you need to track objects without getting too close to them. For example, if you want to use a portable reader to locate items in your store, HF tags are ideal.

Furthermore, HF tags have a limited ability to penetrate metallic objects. It also works well with substances with a medium to high water content. Some of the key applications of these tags include tracking patients' progress in hospitals, tracking library books, and transportation.