---
title: "When does a U.FL jumper beat a trace to the antenna?"
topic: "Trace or U.FL jumper"
answer: "Past about 2.0 cm at 5.5 GHz on a common 4-layer board. Over 10 cm there, a trace delivers 60% of the radio’s power and a coax jumper between two U.FL connectors 83%. On a 2-layer board at 915 MHz, the trace wins up to 13.3 cm."
url: "https://nearfieldnotes.com/notes/ufl-jumper/"
site: "Near Field Notes"
author: "Michael Walker"
note: 25
family: "RF"
published: "2026-11-08"
revised: "2026-11-08"
revision: 1
video: "https://nearfieldnotes.com/videos/ufl-jumper/"
---

Note 25 · [RF](https://nearfieldnotes.com/families/rf/) · Rev 1 · [Watch the video · 0:47](https://nearfieldnotes.com/videos/ufl-jumper/)

Trace or U.FL jumper

# When does a U.FL jumper beat a trace to the antenna?

**Short answer:** Past about 2.0 cm at 5.5 GHz on a common 4-layer board. Over 10 cm there, a trace delivers 60% of the radio’s power and a coax jumper between two U.FL connectors 83%. On a 2-layer board at 915 MHz, the trace wins up to 13.3 cm.

The trace loses the same share of its power in every centimeter, so its wave shrinks all the way to the antenna.

The jumper pays a small toll at each of its two connectors. In between, at 5.5 GHz, its coax loses a fifth as much per centimeter as the trace.

**Note 25’s opening figure: Two routes, one radio.** 10 cm at 5.5 GHz on the 4-layer board

![Note 25’s opening figure: Two routes, one radio](https://nearfieldnotes.com/notes/ufl-jumper/fig-opening.png)

*What the figure shows:* The radio's 5.5 GHz signal crossing 10 cm on the 4-layer board two ways. Along the trace the wave shrinks steadily and 60% of the power arrives. Along the U.FL jumper it drops a little at each connector and barely shrinks in the coax, and 83% arrives. Below, the power left along each route.

The wave along each route, scaled to 1 where it leaves the radio’s match, and below it the power left. The jumper’s U.FL mates sit at its two ends.

**The numbers**

*Power left at 5.5 GHz, as a share of what leaves the radio’s match. The jumper’s 100 mm row is before its second mate.*

| Distance from the radio | Trace | Jumper |
|---|---|---|
| 0 mm | 100% | 96% |
| 20 mm | 90% | 94% |
| 40 mm | 82% | 92% |
| 60 mm | 74% | 90% |
| 80 mm | 67% | 88% |
| 100 mm | 60% | 86% |
| At the antenna | 60% | 83% |

## The board and its two routes

*130 × 56 mm, 4 layers*

A Wi-Fi radio sits at the left end of the board and a chip antenna at the right. Between them are a processor, its DDR and a buck converter, with a USB-C port on the bottom edge.

The radio’s signal leaves its [matching network](https://nearfieldnotes.com/glossary/#g-matching-network) and has 10 cm to cross. One way is a [50 Ω](https://nearfieldnotes.com/glossary/#g-characteristic-impedance) trace on the top layer, routed up along the board’s edge, around the busy middle.

The other is a U.FL receptacle at each end, J1 and J2, with a 100 mm coax jumper plugged between them. It goes straight over the DDR.

**Fig. 25a: One board, two ways across.**

![Fig. 25a: One board, two ways across](https://nearfieldnotes.com/notes/ufl-jumper/fig-25a.png)

*What the figure shows:* Figure 25a: the 130 by 56 mm board rendered twice from above. In the first the radio's output reaches the chip antenna along a 100 mm trace routed up along the top edge. In the second it goes into a U.FL receptacle beside the radio, through a 100 mm coax jumper that arcs over the processor's memory, and into a second receptacle beside the antenna.

The same board with the trace, then with the jumper. The route is drawn over each in its color.

**The numbers**

| Part | What it is |
|---|---|
| U1 | Wi-Fi radio, QFN-48, with its match |
| ANT1 | Chip antenna, 10 × 3.2 mm, in a copper keep-out |
| U2, U3 | Processor and its DDR |
| U4, L2 | Buck converter and its inductor |
| J3 | USB-C receptacle |
| J1, J2 | U.FL receptacles, to Hirose’s U.FL-R-SMT-1 drawing |
| Trace | 0.373 mm wide, 100 mm long, on the top layer over the layer 2 plane |
| Jumper | 1.13 mm coax, 100 mm between plug centers |

A trace’s width is set by how far its plane sits under it. On JLCPCB’s common 4-layer stack the plane is 0.21 mm down, so 50 Ω is 0.37 mm wide. On a 1.6 mm 2-layer board the plane is the bottom layer, 1.53 mm down, and 50 Ω is 2.84 mm wide.

Either way most of the field runs through the FR-4: 87% of its energy on the 4-layer board, 89% on the 2-layer one.

The jumper’s cable is 1.13 mm across. Its field stays inside the shield, in FEP, a plastic that loses far less than FR-4.

**Fig. 25b: Three 50 Ω lines, cut across.**

![Fig. 25b: Three 50 Ω lines, cut across](https://nearfieldnotes.com/notes/ufl-jumper/fig-25b.png)

*What the figure shows:* Figure 25b: three 50 ohm lines cut across, to one scale. The 4-layer board's trace is 0.37 mm wide on 0.21 mm of prepreg over the layer 2 plane. The 1.13 mm coax has a 0.24 mm center conductor in 0.68 mm of FEP inside a 0.90 mm shield. The 2-layer board's trace is 2.84 mm wide on 1.53 mm of FR-4 over the bottom layer.

To one scale. Copper in gold, each line’s signal conductor in its route’s color. The 4-layer section shows only the top of the board’s core.

**The numbers**

*Trace Z₀ and εeff from the 2D field solve, 1 oz copper. Coax from Taoglas’s cable sheet.*

| Line | Conductor | Dielectric | εr | Z₀ | εeff |
|---|---|---|---|---|---|
| 4-layer trace | 0.373 mm | 0.2104 mm, 7628 prepreg | 4.4 | 49.8 Ω | 3.19 |
| 2-layer trace | 2.838 mm | 1.53 mm, FR-4 core | 4.5 | 49.8 Ω | 3.36 |
| 1.13 mm coax | 0.24 mm center | 0.68 mm FEP, 0.90 mm shield | 2.1 | 50 Ω | 2.1 |

## A trace loses in every centimeter

*Copper and FR-4*

A trace gives up the same share of its power in each centimeter. In decibels that adds up along the run:

`L_trace = α d`

where L_trace: trace loss (dB); α: trace loss per length (dB/cm); d: length of the run (cm).

`= 0.223 dB/cm × 10 cm = 2.23 dB`

That is the 4-layer board at 5.5 GHz. Decibels turn back into the share that arrives:

`P/P_0 = 10^(− L /10)`

where P: power that reaches the antenna (W); P_0: power the radio sends (W); L: loss along the route (dB).

`= 10^(−2.23 dB/10) = 60%`

Most of the loss heats the FR-4, and that part grows in step with frequency:

`α_(FR-4) = 8.686 × (π f)/c √(ε_eff) q tanδ`

where α_(FR-4): trace loss per length in the FR-4 (dB/m); f: frequency (Hz); c: speed of light (m/s); ε_eff: effective permittivity the wave sees (No unit); q: share of the field’s energy in the FR-4 (No unit); tanδ: fR-4’s loss tangent, Df (No unit).

`= 8.686 × (π × 5.5 GHz)/(3.00 × 10⁸ m/s) × √(3.19) × 0.87 × 0.018 = 14.1 dB/m = 0.141 dB/cm`

The copper’s part grows only with the square root of frequency, so above 1.8 GHz the FR-4 takes the larger share on the 4-layer board.

**Fig. 25c: Loss in each centimeter.**

![Fig. 25c: Loss in each centimeter](https://nearfieldnotes.com/notes/ufl-jumper/fig-25c.png)

*What the figure shows:* Figure 25c: a 50 ohm trace's loss per centimeter, split into copper and FR-4, on each board at each band. 915 MHz, 4-layer: 0.054 dB/cm, 0.031 in the copper and 0.023 in the FR-4. 915 MHz, 2-layer: 0.030 dB/cm, 0.005 in the copper and 0.025 in the FR-4. 2.4 GHz, 4-layer: 0.116 dB/cm, 0.054 in the copper and 0.063 in the FR-4. 2.4 GHz, 2-layer: 0.075 dB/cm, 0.009 in the copper and 0.066 in the FR-4. 5.5 GHz, 4-layer: 0.223 dB/cm, 0.082 in the copper and 0.141 in the FR-4. 5.5 GHz, 2-layer: 0.161 dB/cm, 0.014 in the copper and 0.148 in the FR-4.

A 50 Ω trace on each board, at each band.

**The numbers**

*1 oz copper, Sq 3.2 µm, loss tangent 0.018, no solder mask.*

| Band, board | Copper | FR-4 | Total, dB/cm | FR-4’s share |
|---|---|---|---|---|
| 915 MHz, 4-layer | 0.031 | 0.023 | **0.054** | 43% |
| 915 MHz, 2-layer | 0.005 | 0.025 | **0.030** | 83% |
| 2.4 GHz, 4-layer | 0.054 | 0.063 | **0.116** | 54% |
| 2.4 GHz, 2-layer | 0.009 | 0.066 | **0.075** | 88% |
| 5.5 GHz, 4-layer | 0.082 | 0.141 | **0.223** | 63% |
| 5.5 GHz, 2-layer | 0.014 | 0.148 | **0.161** | 91% |

Trace loss

### 0.223 dB/cm at 5.5 GHz

**Field marks.** On the 4-layer board at 5.5 GHz the trace loses 0.223 dB/cm: 0.141 in the FR-4 and 0.082 in the copper. Over 10 cm that is 2.23 dB, and 60% arrives.

**Look-alike.** Skin effect. Thin copper gets the blame for trace loss, but on the 4-layer board copper leads only below 1.8 GHz. On the 2-layer board the FR-4 takes 83% or more at all three bands.

**Range.** From 0.054 at 915 MHz to 0.256 dB/cm at 6.5 GHz on the 4-layer board, and 0.030 to 0.190 dB/cm on the 2-layer one. Rogers measured FR-4 microstrip on 0.76 mm at 0.154 dB/cm at 5 GHz. That falls between this page’s 0.206 dB/cm over 0.21 mm of FR-4 on the 4-layer board and 0.147 dB/cm over 1.53 mm on the 2-layer one.

**Habitat.** Cheap 4-layer boards, where the plane sits one thin sheet of prepreg under the top layer and a 50 Ω trace is narrow.

## A jumper pays at its connectors

*Two mates, then the cable*

A jumper’s loss comes in two parts: a fixed toll at its two mates, and its cable, which loses little per centimeter. Linx’s figures for its U.FL jumpers grow with the square root of frequency, so both parts do:

`L_jumper = (A + B d) √(f)`

where L_jumper: jumper loss (dB); A: the two mates’ loss at 1 GHz (dB); B: the cable’s loss per length at 1 GHz (dB/cm); d: length of the run (cm); f: frequency, as a number of GHz (GHz).

`= (0.153 dB + 0.0195 dB/cm × 10 cm) × √(5.5) = 0.82 dB`

That is a 10 cm jumper at 5.5 GHz, and 83% of the power arrives. With no cable at all, the two mates alone would cost 0.36 dB. The jumper starts behind and catches the trace within a few centimeters.

**Fig. 25d: Loss against length.**

![Fig. 25d: Loss against length](https://nearfieldnotes.com/notes/ufl-jumper/fig-25d.png)

*What the figure shows:* Figure 25d: loss against length at 5.5 GHz on the 4-layer board. The trace's line starts at zero and climbs 0.223 dB per cm to 2.23 dB at 10 cm. The jumper's starts at 0.36 dB for its two mates and climbs 0.046 dB per cm to 0.82 dB. They cross at 2.0 cm.

5.5 GHz on the 4-layer board. The circle where the lines cross is the break-even length.

**The numbers**

*5.5 GHz, 4-layer board. The Linx row is its 100 mm figure, 0.34√f dB, against the fit’s 0.82 dB.*

| Length | Trace loss | Jumper loss | Trace delivers | Jumper delivers |
|---|---|---|---|---|
| 0 cm | 0.00 dB | 0.36 dB | 100% | 92% |
| 1 cm | 0.22 dB | 0.41 dB | 95% | 91% |
| 2 cm | 0.45 dB | 0.45 dB | 90% | 90% |
| 4 cm | 0.89 dB | 0.54 dB | 81% | 88% |
| 6 cm | 1.34 dB | 0.63 dB | 73% | 86% |
| 8 cm | 1.78 dB | 0.73 dB | 66% | 85% |
| 10 cm | 2.23 dB | 0.82 dB | 60% | 83% |
| Linx, 100 mm |  | 0.80 dB |  | 83% |

Jumper loss

### 0.36 dB at the mates, then 0.046 dB/cm

**Field marks.** Linx rates its U.FL-to-U.FL 1.13 mm jumpers at 0.34√f dB for 100 mm, 0.56√f for 200 mm and 0.73√f for 300 mm, with f in GHz. A straight line through the three meets zero length at 0.153√f, the two mates, and climbs 0.0195√f per cm, the cable.

**Look-alike.** The cable’s own rating. Taoglas rates 1.13 mm cable at 4.6 dB/m at 5 GHz, so 10 cm looks like 0.46 dB. The whole jumper loses 0.78 dB there, because of its mates.

**Range.** I-PEX’s chart for its 100 mm MHF I jumper reads 0.42 dB at 2.4 GHz and 0.67 dB at 5.8 GHz, below the Linx line’s 0.54 dB and 0.84 dB. With I-PEX’s figures the jumper wins past 1.2 cm at 5.5 GHz on the 4-layer board.

**Habitat.** Boards where the antenna sits far from the radio. u-blox’s JODY-W2 manual puts it plainly: “If traces longer than few centimeters are needed, use a coaxial connector and cable to reduce losses.”

## Where the lines cross

*Every frequency, both boards*

Set the two losses equal and solve for the length where neither route wins:

`d_even = (A √(f))/(α − B √(f))`

where d_even: break-even length (cm); A: the two mates’ loss at 1 GHz (dB); f: frequency, as a number of GHz (GHz); α: trace loss per length (dB/cm); B: the cable’s loss per length at 1 GHz (dB/cm).

`= (0.153 dB × √(5.5))/(0.223 dB/cm − 0.0195 dB/cm × √(5.5)) = 2.0 cm`

Shorter than that, the trace delivers more. Longer, the jumper does. A lower band, or more FR-4 between the trace and its plane, pushes the length out.

**Fig. 25e: Break-even length.**

![Fig. 25e: Break-even length](https://nearfieldnotes.com/notes/ufl-jumper/fig-25e.png)

*What the figure shows:* Figure 25e: the length past which a U.FL jumper delivers more power than a trace, against frequency from 0.9 to 7 GHz. 4-layer board: 4.1 cm at 915 MHz, 2.8 cm at 2.4 GHz, 2.0 cm at 5.5 GHz. 2-layer board: 13.3 cm at 915 MHz, 5.4 cm at 2.4 GHz, 3.1 cm at 5.5 GHz.

From 900 MHz, the bottom of the 915 MHz band, to 7 GHz. A run longer than its board’s line goes to the jumper. The circles are 915 MHz, 2.4 GHz and 5.5 GHz.

**The numbers**

*Break-even length with Linx’s jumper. Shorter runs go to the trace, longer ones to the jumper.*

| Frequency | 4-layer | 2-layer |
|---|---|---|
| 900 MHz | 4.2 cm | 13.5 cm |
| 915 MHz | 4.1 cm | 13.3 cm |
| 2.4 GHz | 2.8 cm | 5.4 cm |
| 5.5 GHz | 2.0 cm | 3.1 cm |
| 7 GHz | 1.8 cm | 2.7 cm |

Break-even length

### 2.0 cm at 5.5 GHz, 13.3 cm at 915 MHz

**Field marks.** On the 4-layer board the jumper wins past 4.1 cm at 915 MHz, 2.8 cm at 2.4 GHz and 2.0 cm at 5.5 GHz. On the 2-layer board, past 13.3 cm, 5.4 cm and 3.1 cm.

**Look-alike.** One length for every board. The same 915 MHz radio breaks even at 4.1 cm on the 4-layer board and 13.3 cm on the 2-layer one. The 2-layer board’s trace sits over more FR-4, so it is 7.6 times as wide, and its copper loses 6 times less.

**Range.** From 1.8 cm at 7 GHz on the 4-layer board to 13.5 cm at 900 MHz on the 2-layer one.

**Habitat.** 915 MHz radios on 2-layer boards, where a trace wins up to 13.3 cm. Wi-Fi radios on common 4-layer boards, where the jumper wins once the antenna is more than a couple of centimeters away.

## Shielding, hands and cost

*What loss leaves out*

The jumper’s coax is shielded, so it can cross parts the trace has to avoid. In Fig. 25a the trace detours along the board’s top edge, clear of the processor, its DDR and the buck. The jumper runs straight across the DDR and past the buck.

Fast digital parts and ports make noise in a radio’s band. Intel measured the 2.4 GHz noise floor about 20 dB higher beside a USB 3.0 hard drive, and about 25 dB higher at a notebook’s USB 3.0 port. A route that picks up that noise brings it to the antenna.

The catch is the cable. The receptacles go on with the other parts, but the cable is plugged in by hand. Hirose, I-PEX and TE test their mates to 30 cycles. At 1,000 pieces, two receptacles and a cable cost $1.26 to $3.33 at Digi-Key, as listed on 5 November 2026. That price is for a 50 mm cable, half the length of the board’s. The trace costs only its copper.

## Choosing a route

*Loss, noise and the link*

Length and band settle most cases. When they don’t, what lies along the route and how much range you need decide.

Key to the RF route

### Trace or jumper?

1. 1a The run is shorter than its board’s line in Fig. 25e Trace
2. 1b Longer Go to 2
3. 2a The straight path crosses DDR, a buck or USB 3 Jumper
4. 2b The path is clear Go to 3
5. 3a The link needs the decibels the trace loses Jumper
6. 3b It can spare them Trace

The board in Fig. 25a ends at 2a: 10 cm at 5.5 GHz, past the DDR. Its jumper saves 1.41 dB over the trace. Range in free space grows as `10^(1.41 dB/20) = 1.18`, so that is 18% farther.

## Route it yourself

*Three bands, two boards, 1 to 30 cm*

Choose a band, a board and a length. Each line is the share of the radio’s power that reaches the antenna. The jumper’s starts lower, after its mates, and falls more slowly.

Where the lines cross is the break-even length of Fig. 25e.

**Note 25’s explorer: Power delivered against length.**

![Note 25’s explorer: Power delivered against length](https://nearfieldnotes.com/notes/ufl-jumper/fig-explore.png)

*What the figure shows:* Power that reaches the antenna against the length of the run, from 0 to 30 cm, for the chosen band and board. The trace's line falls steadily. The jumper's starts lower, after its two mates, and falls slowly. The circle is where they cross.

Power that reaches the antenna, as a share of what leaves the radio’s match. The circle is where the lines cross.

**The numbers**

*Power delivered, trace / jumper.*

| Band, board | 2 cm | 5 cm | 10 cm | 20 cm | 30 cm | Break-even |
|---|---|---|---|---|---|---|
| 915 MHz, 4-layer | 98% / 96% | 94% / 95% | 88% / 93% | 78% / 89% | 69% / 85% | 4.1 cm |
| 915 MHz, 2-layer | 99% / 96% | 97% / 95% | 93% / 93% | 87% / 89% | 81% / 85% | 13.3 cm |
| 2.4 GHz, 4-layer | 95% / 93% | 87% / 91% | 76% / 88% | 58% / 82% | 45% / 77% | 2.8 cm |
| 2.4 GHz, 2-layer | 97% / 93% | 92% / 91% | 84% / 88% | 71% / 82% | 60% / 77% | 5.4 cm |
| 5.5 GHz, 4-layer | 90% / 90% | 77% / 87% | 60% / 83% | 36% / 75% | 21% / 67% | 2.0 cm |
| 5.5 GHz, 2-layer | 93% / 90% | 83% / 87% | 69% / 83% | 48% / 75% | 33% / 67% | 3.1 cm |

#### Conditions

- **Board:** 130 × 56 mm, 1.6 mm thick. The 4-layer case uses JLCPCB’s JLC04161H-7628 stack: 0.2104 mm of 7628 prepreg under the top layer, εr 4.4. The 2-layer case puts the trace 1.53 mm over the bottom layer, εr 4.5.
- **Trace:** 50 Ω microstrip, 1 oz copper, no solder mask: 0.37 mm wide on the 4-layer board and 2.84 mm on the 2-layer one, both 49.8 Ω by the 2D solve. Loss tangent 0.018 and copper roughness Sq 3.2 µm, the Hammerstad roughness model.
- **Jumper:** Linx’s CSI-UFFR U.FL-to-U.FL 1.13 mm jumpers, as the straight-line fit of their 100, 200 and 300 mm figures in the jumper’s formula above. The opening figure splits the mates’ share evenly between its two ends.
- **Bands:** 915 MHz, 2.4 GHz taken at 2.45 GHz, and 5.5 GHz.
- **Trace loss:** A 2D field solve of each cross-section: copper by incremental inductance, FR-4 by the share of the field’s energy in it.
- **Opening:** The trace’s wave is the field in the FR-4 under its center line, from an openEMS run of the 10 cm 4-layer line at 5.5 GHz. That run’s [S21](https://nearfieldnotes.com/glossary/#g-s21) is −2.21 dB, 60% delivered, and its field falls 0.221 dB/cm against 0.223 dB/cm from the 2D solve. The power line below it follows that fitted fall. Its wavelength on the board is 29.9 mm. The jumper’s wave uses the coax’s wavelength from an openEMS run of the cable, 36.5 mm, and the Linx loss.
- **Video:** The video used an earlier run of the 2D solve that read copper loss about 13% low. Its 61% is 60% here, and its 2.1, 3.0 and 14 cm are 2.0 cm, 2.8 cm and 13.3 cm.
- **Renders:** Blender. Parts from their datasheet outlines, the U.FL receptacles from Hirose’s drawing.

Simulated only. Nothing on this page has been measured on a board yet.

#### Limits

- Linx rates these jumpers from DC to 3 GHz. Above that its square-root law is carried past its range. I-PEX’s 5.8 GHz figure is lower.
- TE allows up to 0.24 dB for each of its U.FL-style mates to 6 GHz, 0.48 dB for two, more than the Linx line’s 0.36 dB at 5.5 GHz.
- Each mate’s [reflection](https://nearfieldnotes.com/glossary/#g-reflection) is inside the jumper’s figures, not modeled on its own.
- Solder mask over the trace would add a little loss.
- Noise pickup isn’t simulated. Intel’s figures are near-field probe readings in the 2.4 GHz band, not noise on a trace.
- Bends and vias aren’t counted. A trace that changes layers pays at each via too, as [Note 17](https://nearfieldnotes.com/notes/via-stubs/) shows.

#### Files

- post/site.py Trace loss on both boards, the jumper’s line and every break-even length on this page
- post/tradeoff.py The Linx and I-PEX jumper fits
- sim/stack.py The two stack-ups and their 50 Ω widths
- sim/fields.py The openEMS runs of the 10 cm line and the coax at 5.5 GHz
- render/site.py The board renders in Fig. 25a
- render/board.py The board, its parts and both routes

#### Sources

- [Linx, CSI-UFFR U.FL-to-U.FL 1.13 mm jumper drawing, its insertion loss](https://www.farnell.com/cad/3971145.pdf)
- [I-PEX, MHF series sheet, its jumpers’ insertion loss against length](https://www1.futureelectronics.com/doc/I-PEX/MHFSeries.pdf)
- [I-PEX, MHF I product specification, its 30 cycles](https://www.i-pex.com/sites/default/files/downloads/pdf/PRODSPEC_MHF_I_PRS-1726-09EN.pdf)
- [Hirose, U.FL series catalog, its 30 cycles and VSWR](https://www.farnell.com/datasheets/3993933.pdf)
- [TE, RF coax connectors catalog, the UMCC’s 0.24 dB and 30 cycles](https://mm.digikey.com/Volume0/opasdata/d220001/medias/docus/2583/RF%20Coax%20Connectors.pdf)
- [Taoglas, 1.13 mm cable specification, its sizes and loss per meter](https://www.taoglas.com/specifications/300115B000098A_Taoglas.pdf)
- [JLCPCB, impedance calculator, the 7628 stack](https://jlcpcb.com/impedance)
- [Nan Ya NP-155F family datasheet, the 7628 prepreg’s 0.018](https://www.eurocircuits.com/content/uploads/2024/05/NP-155FTL_NP-155FR_NP-155FB.pdf)
- [OSH Park, 2-layer service, its FR-4’s 4.5](https://docs.oshpark.com/services/two-layer/)
- [Rogers, copper foils, standard foil’s Sq 3.2 µm](https://www.rogerscorp.com/-/media/project/rogerscorp/documents/advanced-electronics-solutions/english/properties---detailed-characteristics/copper-foils-for-high-frequency-circuit-materials.pdf)
- [Rogers, RO4003 insertion loss compared with other materials, measured FR-4](https://www.rf-microwave.com/app/resources/uploads/laminates/RO4003-application-note.pdf)
- [u-blox, JODY-W2 system integration manual](https://content.u-blox.com/sites/default/files/JODY-W2_SIM_UBX-18068879.pdf)
- [Intel, USB 3.0 radio frequency interference on 2.4 GHz devices](https://www.usb.org/sites/default/files/327216.pdf)
- Digi-Key prices at 1,000, as listed on 5 November 2026: [TE 2337019-1](https://www.digikey.com/en/products/detail/te-connectivity-amp-connectors/2337019-1/9974052), [Hirose U.FL-R-SMT-1](https://www.digikey.com/en/products/detail/hirose-electric-co-ltd/U-FL-R-SMT-1-10/2391570), [I-PEX 8-24-0113](https://www.digikey.com/en/products/detail/i-pex/8-24-0113/25021146), [Hirose U.FL-2LPHF6-068N1T-A-50](https://www.digikey.com/en/products/detail/hirose-electric-co-ltd/U-FL-2LPHF6-068N1T-A-50/12340946)
- [openEMS, the 3D field solver](https://www.openems.de/)

What should the next note be? [Ask for one](https://nearfieldnotes.com/#ask-for-a-note)

---

Source: https://nearfieldnotes.com/notes/ufl-jumper/

Cite as: Michael Walker, “Trace or U.FL jumper”, Near Field Notes, Note 25, Rev 1, 8 Nov 2026. https://nearfieldnotes.com/notes/ufl-jumper/

Figures: free to reuse under CC BY 4.0 (https://nearfieldnotes.com/license/). Each one's image is linked under its name. Credit Michael Walker, Near Field Notes, and link the figure: this address plus #fig- and its number, like https://nearfieldnotes.com/notes/ufl-jumper/#fig-25a.