UHF RFID for Warehouses, Dock Doors & Portals
Plan RFID for warehouse management: fixed readers and circular antennas at dock doors, conveyor tunnels, handheld cycle counts and on-metal asset tags.
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GM-140 Ultra-Thin Low-Power UHF RFID Module, 18–26 dBm, TTL
50 × 50 mm integrated UHF RFID module for handhelds and desktop card issuers: 18–26 dBm, 100–250 mA, TTL UART, reads up to 3 m with no heatsink. US and EU versions.
- 18–26 dBm output with read distances up to 3 m
- Low draw: 100–250 mA at 3.5–5 V DC, no heatsink required
- Ultra-thin reader section (1.22 mm) with low-profile back-side components
- EPC Gen2 / ISO 18000-6C, more than 50 tags/s
- TTL UART at 115200 bps (default) or 38400 bps
- Frequency
- 902–928 MHz (US) / 865–868 MHz (EU)
- Output power
- 18–26 dBm
- Read range
- Up to 3 m
- Interface
- TTL UART
- Power
- 3.5–5 V DC, 100–250 mA
- Dimensions
- 50 × 50 × 7 mm
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Ultra-Thin Low-Power UHF RFID Module, 18–26 dBm, TTL: overview
The GM-140 is an ultra-thin, low-power UHF RFID module for battery handhelds, desktop card issuers and other compact devices where a 33 dBm engine would cost too much power and space. It is built around a PR9200 single-chip UHF reader, draws 100–250 mA from a 3.5–5 V DC supply and needs no extra heat dissipation.
Output power runs from 18 to 26 dBm, enough for read distances of up to 3 m with suitable tags. The module handles EPC Gen2 / ISO 18000-6C tags at more than 50 per second and exchanges data over a TTL UART, 115200 bps by default or 38400 bps. As an integrated module it measures 50 × 50 × 7 mm (±1 mm); the reader section is only 1.22 mm thick and the back-side components are kept low, which helps in slim enclosures.
Two band versions are offered. GM-140-US targets the FCC 902–928 MHz band, and GM-140-EU targets ETSI EN 302 208 at 865–868 MHz. Region plans for China, Japan, Korea, Malaysia and Taiwan are listed as well.
Integration notes
The supporting circuit is simple: a regulated 3.5–5 V rail and a UART link to your MCU. Operating temperature is −20 to +70 °C, with storage from −20 to +80 °C and 15–90% relative humidity. Request the pinout and command overview with your sample so your firmware team can start before volume orders.
More features
- Operates from −20 to +70 °C
- US 902–928 MHz and EU 865–868 MHz versions
GM-140 specifications
RF & protocols
| Reader IC | PR9200 single-chip UHF reader |
|---|---|
| Frequency range | 902–928 MHz (US version), 865–868 MHz (EU version) |
| Region plans listed | FCC (US, Canada), ETSI EN 302 208 (Europe), China, Japan, Korea, Malaysia, Taiwan |
| Air protocol | EPCglobal UHF Class 1 Gen 2 / ISO 18000-6C |
| Output power | 18–26 dBm |
Performance
| Read range | Up to 3 m (tag dependent) |
|---|---|
| Read speed | > 50 tags/s |
Interfaces
| Host interface | UART, TTL level |
|---|---|
| Baud rate | 115200 bps (default), 38400 bps |
Electrical
| Supply voltage | 3.5–5 V DC |
|---|---|
| Operating current | 100–250 mA |
| Cooling | No additional heat dissipation required |
Mechanical & environment
| Dimensions | 50 × 50 × 7 mm (±1 mm) |
|---|---|
| Reader-section thickness | 1.22 mm |
| Operating temperature | −20 to +70 °C |
| Storage temperature | −20 to +80 °C |
| Relative humidity | 15–90% |
Order codes
| SKU | Band / regulation | Output power | Typical target device |
|---|---|---|---|
| GM-140-US | FCC, 902–928 MHz | 18–26 dBm | UHF card issuers, handheld terminals |
| GM-140-EU | ETSI EN 302 208, 865–868 MHz | 18–26 dBm | UHF card issuers, handheld terminals |
Specifications can change between production batches. Confirm the current revision with us before placing volume orders.
Ordering options
Quote the SKU that matches your frequency, interface and mounting. Not sure? Send us your controller model and we will pick the variant for you.
| SKU | Configuration | Actions |
|---|---|---|
| GM-140-US | Integrated ultra-thin module, US FCC band (902–928 MHz), TTL UART | |
| GM-140-EU | Integrated ultra-thin module, EU ETSI band (865–868 MHz), TTL UART |
Where the GM-140 is used
- UHF engine for a battery-powered handheld inventory scanner
- Desktop UHF card issuer or tag encoder running from a regulated USB supply
- Compact asset check-in terminal on a service counter
- Slim wall-mounted reader where depth behind the cover is limited
RFID Asset & Tool Tracking
Build an RFID asset tracking system: on-metal, ceramic and tie-on tags matched to each asset, handheld audits, smart cabinets and IP67 HF heads for tooling.
GM-140 FAQ
Does the GM-140 need a heatsink?
No. At 18–26 dBm and 100–250 mA it is specified to run without additional heat dissipation, which suits sealed handheld enclosures.
How far does it read?
Up to 3 m with suitable tags. For lane or dock-door distances, choose a 33 dBm module such as the GM-130 instead.
Can it run from a USB port?
Its 100–250 mA draw fits within a standard USB port's budget, but the specified supply range ends at 5 V DC and USB bus voltage can sit slightly above that. Regulate the rail into the 3.5–5 V window rather than feeding raw USB power.
Which version should I order?
GM-140-US for countries that follow FCC rules (902–928 MHz) and GM-140-EU for ETSI countries (865–868 MHz). For other markets, give us the country and we check the region plan.
Before you buy
Related buyer guides
UHF RFID Frequency by Country: 902–928 MHz vs 865–868 MHz and Other Bands
Compare UHF RFID reader bands by country, including US, EU, UK, China, India and Japan. Understand ERP, EIRP, channel conditions and radio approvals.
How to Wire a Long-Range UHF Reader to an Access Controller or Barrier
Wire a UHF reader's D0, D1 and ground to your controller, match 26/34-bit Wiegand, size 12 V power and trigger the barrier by relay. Diagrams included.
Does RFID Work on Metal? How to Choose On-Metal Tags
Yes, RFID works on metal with tags built for it. See why metal detunes standard tags, compare ABS, PCB, ceramic and label tags, and test read range properly.
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