The Ebyte TXGB series is a GPS L1 + BeiDou B1 GNSS antenna pair covering 1575.042±1.023MHz and 1561.098±2.046MHz at 50Ω, comprising the TXGB-AZ-300 active radome antenna (50×38×16.7mm radome, built-in LNA with 28±2dB gain, <1.5dB noise figure, 3m RG174 cable to SMA-J, DC 3~5V / ≤15mA) and the TXGB-JKD-20Y 200mm foldable whip with 8dBi gain and integrated active element, both VSWR ≤1.5 for vehicle, fleet and portable positioning terminals.
Key Features & Advantages
- Dual-Constellation GPS L1 + BeiDou B1 Coverage: Both models operate on 1575.042±1.023MHz (GPS L1 / Galileo E1 / QZSS) and 1561.098±2.046MHz (BeiDou B1) with >10MHz antenna bandwidth per band, so GNSS receivers can lock satellites from two constellations simultaneously for faster fix and better availability under urban canyon conditions.
- Built-in Low-Noise Amplifier (LNA): The TXGB-AZ-300 integrates an LNA offering 28±2dB gain (excluding feeder), <1.5dB noise figure, ±1.0dB in-band flatness and 35dBc min out-of-band rejection at F0±100MHz — this compensates the 3m RG174 cable loss and preserves receiver sensitivity over long internal runs.
- Right-Hand Circular Polarization (AZ-300): GNSS downlinks are RHCP; the AZ-300 matches that polarization to reject ground-reflected and multipath energy, which is why a flat radome antenna mounted top-up outperforms a vertical whip for accurate positioning.
- Foldable Whip for Steerable / Mobile Use: The TXGB-JKD-20Y provides 8dBi gain in a 200mm TPEE whip with an integrated active element and SMA-J rotary joint — convenient when the antenna must be folded for transport, angled, or mounted on a small enclosure with limited headroom.
- Standard SMA-J Interface, 50Ω Matched: Both antennas terminate in SMA-J (male thread, pin) to plug straight into GNSS modules, vehicle terminals and data loggers; VSWR ≤1.5 keeps reflection loss low at both centre frequencies.
- Low Active-Bias Budget: The AZ-300 draws ≤15mA at DC 3.3V (rated 3~5V), which most GNSS modules already supply through the RF line as a bias tee; no extra power wiring is required.
Core Specifications
Specifications compiled from the official Ebyte per-model spec tables. Note: the "28" figure for TXGB-AZ-300 is LNA amplifier gain in dB (28±2dB, excluding feeder), not passive antenna dBi gain.
| Parameter | TXGB-AZ-300 (Active Mount) | TXGB-JKD-20Y (Foldable Whip) |
|---|---|---|
| Antenna type | GPS / BeiDou positioning antenna, black radome puck for external mounting | Foldable omnidirectional rubber whip, black |
| Frequency range | 1575.042±1.023MHz (GPS L1) & 1561.098±2.046MHz (BeiDou B1) | 1575.042±1.023MHz & 1561.098±2.046MHz |
| Antenna bandwidth | GPS-L1 >10MHz; BD-B1 >10MHz | GPS-L1 >10MHz; BD-B1 >10MHz |
| Gain | LNA gain 28±2dB (excluding feeder) | 8dBi antenna gain; 20dB LNA gain (excluding feeder) |
| Noise figure | ||
| In-band gain flatness | ||
| Out-of-band rejection | 35dBc min at F0±100MHz | |
| Voltage standing wave ratio | ||
| Polarization | Right-hand circular (RHCP) | Vertical (linear) |
| Input impedance | 50Ω | 50Ω |
| Power handling | 20W | 20W |
| DC supply (active) | DC 3~5V, ≤15mA at DC 3.3V | DC 3~5V |
| Dimensions | 50×38×16.7mm radome | 200mm overall length |
| Feeder | RG174, 3m | TPEE jacket, no separate feeder |
| Weight | 61g (61±2g) | 22g |
| Connector | SMA-J (male thread, pin) | SMA-J (male thread, pin) |
| Operating / storage temperature | -30°C ~ +75°C | -40°C ~ +85°C |
Product Selection Guide
Selection Notice: These are receive-only GNSS positioning antennas for the GPS L1 (1575.42MHz) and BeiDou B1 (1561.098MHz) broadcast bands — they are not for Sub-1GHz / 2.4GHz / 4G data links, and no transmit licensing applies. For best accuracy choose the RHCP flat radome AZ-300 with a clear view of the sky (roof, dashboard, mast top); choose the foldable JKD-20Y when space, headroom or repeated folding/transport dominates. Both are active antennas — verify your receiver board can supply the DC bias (3~5V) on the RF line, otherwise add an external bias tee.
| Model | Form Factor | Gain | Polarization | Cable / Mount | Best For |
|---|---|---|---|---|---|
| TXGB-AZ-300 | 50×38×16.7mm black radome puck | 28±2dB LNA | RHCP | 3m RG174 + SMA-J; external mount | Vehicle & fleet GPS/BeiDou terminals, navigation, dashcams, long cable runs inside metal bodies |
| TXGB-JKD-20Y | 200mm foldable rubber whip (22g) | 8dBi / 20dB LNA | Vertical linear | Direct SMA-J rotary joint | Portable trackers, drones, outdoor positioning terminals, equipment needing a steerable or foldable antenna |
Industrial Installation & Wiring
1. Sky view first: GNSS performance is set by line-of-sight. Mount the AZ-300 flat, marking-side-up, on a horizontal surface with an unobstructed view above roughly 15° elevation. Keep it at least 20~30cm away from other antennas, metal rails, inverters and DC-DC converters.
2. Metal roofs and enclosures: A puck antenna mounted directly on a conductive surface works as intended (the roof acts as ground plane). Inside a fully metal cabin or behind a heat-insulating / metallised windscreen, satellite signal is attenuated — relocate externally or use the JKD-20Y whip outside the enclosure.
3. RF connection: Both antennas terminate in SMA-J (male thread, pin); screw onto the receiver's SMA-K (female thread, jack) RF pad by hand plus a light quarter turn. Do not lever or over-torque a module's SMA island — it will crack the solder joints.
4. DC bias for the active antenna: The AZ-300 needs DC 3~5V (≤15mA at 3.3V) on the centre conductor. Most GNSS receiver boards provide this through a bias tee; if yours does not, insert an external 3~5V bias tee between antenna and receiver, otherwise the internal LNA stays off and sensitivity drops by roughly the cable loss.
5. Cable management: Route the 3m RG174 away from motor power leads, VFD output cables and switching supplies; if it must cross them, cross at 90°. Do not coil surplus cable into a tight loop near the receiver input.
Practical Application Scenarios
1. Fleet, Taxi and Bus Positioning / Passive Announcements
Externally mounted AZ-300 pucks feed GPS+BeiDou fixes to on-board 4G/GNSS terminals in taxis, buses and driving-school vehicles, supporting mileage logging, geofencing, and stop-announcement triggers even when the receiver box sits deep inside the metal body — the LNA offsets the 3m feeder loss.
2. After-Market Vehicle Navigation, Dashcams and Teardown-Safe Retrofit
DVD navigation units, telematics dongles and repair-shop diagnostic tools use the radome antenna behind a dashboard or on a windshield; the foldable whip variant suits plug-and-play retrofits where no drilling is allowed.
3. Drones, Robotics and Portable Field Terminals
The 22g foldable JKD-20Y keeps weight and stowage volume minimal on UAVs, survey poles, handheld data collectors and asset trackers, and can be angled toward the sky when the mounting orientation is constrained.
4. IoT Time-Synchronisation and Asset Tracking Nodes
Sub-1GHz DTUs, LoRa nodes and RTU gateways frequently need GNSS-derived timestamps and location stamps; the compact active puck provides both to the receiver section of combined module boards over a single coax with bias.
FAQ Section
Q1: Is the 28dBi figure passive antenna gain or LNA gain?
It is LNA (amplifier) gain: the official spec table lists "Gain (excluding feeder) 28±2dB" under the LNA characteristics block, together with noise figure <1.5dB and ±1.0dB in-band flatness. Passive ceramic patch antennas of this size typically provide only a few dBi of gain; the 28dB number describes the amplifier that restores signal after cable loss and receiver front-end insertion loss.
Q2: Will these antennas work for GLONASS, Galileo or BeiDou B2/B3?
The published pass bands are GPS L1 1575.042±1.023MHz and BeiDou B1 1561.098±2.046MHz. Galileo E1 shares the 1575.42MHz band, so E1 reception is generally possible; GLONASS G1 (around 1602MHz) and BeiDou B2/B3 lie outside the specified bandwidth. For multi-constellation, multi-band receivers select a dedicated multi-band antenna.
Q3: My receiver already has a patch antenna — what does adding this active antenna improve?
Nothing, unless the antenna sits far from the receiver. Active antennas are chosen precisely to move the radiating element to the best sky position while the receiver stays inside a metal enclosure: without the LNA, 3m of RG174 plus connector loss can cost several dB of link margin and lengthen cold starts.
Q4: The receiver does not output bias voltage — can the antenna still be used?
Yes, with an in-line bias tee injecting DC 3~5V onto the coax centre conductor, keeping within the ≤15mA budget at 3.3V. Do not exceed 5V. If no bias is applied at all, the LNA is unpowered and the assembly behaves as a passive antenna with cable loss.
