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• Exploring Nomad Terminal GPS Antenna Improvement From 8.2 to 5.2 Seconds

  Makerfabs • 09/01/2026 at 08:39 • 0 comments

  During product development, we tested the GPS antenna performance of two design generations.

  The first-generation design was functional, but its reception performance was not as good as expected. Based on the test results, we analyzed the antenna placement and redesigned the GPS antenna structure for the second generation. This redesign improved the Time to First Fix (TTFF) from 8.2 s to 5.2 s.

  
  

  V1.0: Passive Ceramic Antenna

  The first-generation product used a passive ceramic antenna.

  To save space, it was mounted directly on the PCB, which made the product compact, but the actual GPS reception performance was not satisfactory.

  The display is positioned directly above the antenna, with metal components behind it, which negatively affects GPS signal reception.

  The battery and other components were too close to the antenna.

  The V1.0 test results were:

  • Time to First Fix (TTFF): 8.2 s
  • Visible satellites after 1 minute: approximately 15

  
  

  V1.1: Redesign for Better Reception

  Based on the first-generation test results, we redesigned the GPS antenna structure for the second generation.

  The second-generation design uses an active ceramic antenna. Unlike a passive antenna, an active antenna integrates a low-noise amplifier (LNA) to boost the received RF signal before it reaches the GNSS receiver, helping improve reception in weak-signal environments.

  The antenna placement was also changed:

  • The antenna is positioned above the PCB and faces upward, with no major obstructions around it.
  • Whether the device is held in your hand or placed upright, the antenna remains pointed toward the sky.

  This redesign directly addressed the main limitations identified in the V1.0.

  
  

  Small active ceramic Antenna Test

  We first tested a small active ceramic antenna in the V1.1 design.

  The results showed a clear improvement compared with the first-generation passive antenna:

  • Time to First Fix (TTFF): 5.8 s.
  • Visible satellites after 1 minute: approximately 27

  This confirmed that the active antenna design and upward-facing placement were effective.

  However, the small antenna still did not fully meet our expectations. Although the performance was better, there was still room to improve signal strength and satellite visibility in some environments.

  For this reason, we continued testing with a larger active ceramic antenna.

  
  

  Large active ceramic Antenna Test

  After confirming the improvement achieved with the small active ceramic antenna, we continued testing with a larger active ceramic antenna. Compared with the smaller antenna, the larger ceramic antenna provides a larger effective receiving area and can achieve higher antenna efficiency and better signal reception performance in our design.

  The test results showed a further improvement with the larger active ceramic antenna.

  • Time to First Fix (TTFF): 5.2 s
  • Visible satellites after 1 minute: approximately 32

  This result met our expectations much better than the first-generation design and the second-generation small antenna.

  Comparison

  All antenna versions were tested under the same test conditions using the same GNSS receiver and test environment. In our test, the TTFF improved from 8.2s to 5.2s.

  Solution	Antenna Type	Antenna Type	Time to First Fix	Satellites Detected(1 min)
  V1.0	Passive ceramic antenna	Beneath the display, close to the battery	8.2s	15
  V1.1(small antenna)	Active ceramic antenna	Mounted above the PCB, facing upward	5.8s	27
  V1.1(large antenna)	Active ceramic antenna	Mounted above the PCB, facing upward	5.2s	32

• From Ceramic to FPC: LoRa / Sub-GHz Antenna Optimization

  Makerfabs • 08/17/2026 at 07:16 • 0 comments

  During the development of the Nomad Terminal, the LoRa / Sub-GHz antenna went through several design iterations.

  For a compact handheld device, antenna performance is not determined by the antenna itself. The surrounding PCB, ground plane, battery, display, enclosure, and even the way the user holds the device can all affect the final RF performance.

  To improve the overall LoRa RF performance while keeping the product compact and practical, we evaluated several antenna solutions and connection methods during development:

  Ceramic Antenna → FPC Antenna + Coaxial Cable → FPC Antenna + Pogo Pin

  Each revision addressed limitations found in the previous design.

  V1.0--Ceramic Antenna

  For the first hardware revision, we used a ceramic antenna for the LoRa radio. The ceramic antenna was integrated directly onto the PCB, providing a simple and compact RF solution.

  Advantages	Disadvantages
  Compact and easy to integrate	Antenna performance is highly dependent on PCB layout
  No additional RF cable required	Sensitive to nearby components and materials

  The biggest advantages of ceramic antennas are their simplicity, compactness, and ease of integration. For early product prototypes, this is a relatively straightforward solution.

  However, after assembling the complete device, we found that the ceramic antenna was located directly beneath the display module. The nearby conductive structures of the display caused antenna detuning and RF shielding, significantly degrading the overall antenna performance.

  V1.1 — FPC Antenna + Coaxial Cable

  In the second revision, we evaluated an FPC antenna. The key advantage of the FPC antenna was that it decoupled antenna placement from the main PCB layout,  compared with a ceramic antenna mounted directly on the PCB, an FPC antenna can be positioned more freely inside the enclosure.

  Advantages	Disadvantages
  Can be positioned away from the main PCB	Requires an additional RF connection
  Easier to avoid the battery and other components	Transmission-line effects and impedance matching need to be considered

   The FPC solution improved placement flexibility and helped avoid blockage from the display by allowing the antenna to be positioned more freely inside the enclosure.

  However, it introduced a new RF challenge: the connection between the antenna and the main PCB.

  In this design, the FPC antenna is connected to the main PCB through a 50 Ω coaxial cable. Although coaxial cable provides a well-controlled RF transmission path, it introduces additional insertion loss, connectors, routing space, and assembly complexity. When the coaxial cable length exceeds approximately 3 cm, the cable shield can begin to behave as part of the RF ground or counterpoise, making the overall antenna performance more dependent on the cable length and routing. Since this is a handheld device, and for aesthetic reasons, we didn’t want to use a long, high-performance rod antenna, so we made another revision.

  
  V1.2 — FPC Antenna + Pogo Pin

  For the third revision, we replaced the coaxial connection with a dual-Pogo-Pin RF connection, using one pin for the RF feed and the second pin for the ground return. This means the antenna is no longer referenced to the antenna side as ground, but instead uses the PCB as the reference ground.

  Advantages	Disadvantages
  Compact RF connection with direct access to the PCB ground reference	Requires careful mechanical integration
  It's much simpler than FPC + coaxial cable	It is important to ensure reliable contact with the pogo pins.

  
  

  This approach gave us a better combination of the advantages from the previous two designs. The FPC antenna provided the mechanical flexibility we needed, while the Pogo Pin allowed us to keep the RF connection extremely short.

  Before evaluating the antenna in the final handheld device, we also characterized the antenna using laboratory RF measurement equipment. The antenna was measured using a network analyzer (Agilent...

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