Move Radio Reception Out of the Head Unit

Reduce Cost, Complexity, and EMI with Remote Tuner Architecture

Modern Infotainment Systems Are Outgrowing Conventional Radio Architectures

Today’s in-vehicle infotain­ment systems integ­rate an increas­ing range of func­tions within highly con­fined spaces. When radio recep­tion is imple­men­ted dir­ectly in the head unit—alongside stream­ing, nav­ig­a­tion, voice pro­cessing, and connectivity—system com­plex­ity increases sig­ni­fic­antly.

This con­cen­tra­tion of func­tions places growing pres­sure on the overall system archi­tec­ture, intro­du­cing cas­cad­ing engin­eer­ing chal­lenges and increas­ing integ­ra­tion effort across vehicle plat­forms and region­al vari­ants.

Radio recep­tion is cent­ral­ized in the head unit, driving RF and integ­ra­tion com­plex­ity

Key Challenges of Conventional Head-Unit–Centric Architectures

Thermal Density

Increas­ing radio and con­nectiv­ity func­tions con­cen­trated in the head unit create thermal stress in tightly packed envir­on­ments, lim­it­ing per­form­ance and long-term reli­ab­il­ity.

EMI / RF Interference

Prox­im­ity to high-power elec­tron­ics increases elec­tro­mag­net­ic inter­fer­ence, neg­at­ively impact­ing radio recep­tion quality and overall system sta­bil­ity.

Antenna Complexity

Long coaxial cable runs, extern­al antenna amp­li­fi­ers, and addi­tion­al con­nect­ors increase system com­plex­ity, weight, and integ­ra­tion effort.

Higher System Cost

Redund­ant com­pon­ents and complex wiring archi­tec­tures inflate BOM, assembly, and val­id­a­tion costs.

Hirschmann Car Communication —
Remote Tuner Module (RTM)

Digit­al­iz­a­tion of Broad­cast Radio Recep­tion Enables a Sim­pli­fied System Archi­tec­ture

As con­ven­tion­al radio archi­tec­tures reach their limits, modern vehicles require a new approach to radio integ­ra­tion. The Hirschmann Car Com­mu­nic­a­tion Remote Tuner Module (RTM) addresses the lim­it­a­tions of con­ven­tion­al radio archi­tec­tures by intro­du­cing a fun­da­ment­al archi­tec­tur­al shift. The RTM relo­cates radio recep­tion from the head unit to a ded­ic­ated module posi­tioned near the vehicle’s antenna system.

One Architectural Change. System-Wide Impact

This dis­trib­uted archi­tec­tur­al approach allows the Remote Tuner Module (RTM) to be posi­tioned at the roof, C‑pillar, or trunk lid, close to the antenna system where recep­tion con­di­tions are optimal. As a ded­ic­ated radio recep­tion module, RTM receives broad­cast signals (AM/FM/DAB/DAB+), pro­cesses them in an RF-optim­ized envir­on­ment, con­verts them into digital audio, and trans­mits the signal to the head unit via a single digital inter­face.

By fully off­load­ing radio recep­tion from the head unit, RTM elim­in­ates the need for antenna amp­li­fi­ers, RF filters, shield­ing, and complex RF cabling within the infotain­ment domain. The head unit is sim­pli­fied by design, allow­ing it to focus on pro­cessing, user inter­ac­tion, and digital ser­vices.

With clean digital audio provided by RTM and simple control com­mands exchanged between systems, infotain­ment func­tions such as stream­ing, nav­ig­a­tion, voice pro­cessing, and con­nectiv­ity operate without RF inter­fer­ence. This enables greater design flex­ib­il­ity, improved system robust­ness, and con­sist­ent form factors across vehicle plat­forms.

Dis­trib­uted RTM Place­ment Across the Vehicle, Close to the Antenna System

Key Architectural Benefits

Lower System Cost

Elim­in­at­ing antenna amp­li­fi­ers, redu­cing coaxial cables and con­nect­ors, and sim­pli­fy­ing assembly lowers overall system cost. A plug-and-play approach further reduces devel­op­ment and val­id­a­tion effort.

Optimized RF Performance

Loc­at­ing radio recep­tion close to the antenna ensures high signal quality and pre­serves integ­rity through digital trans­port, while decoup­ling per­form­ance from head-unit con­straints.

Simplified Integration

Designed for easy replace­ment of con­ven­tion­al antenna amp­li­fi­ers, the solu­tion integ­rates with minimal system changes. A sim­pli­fied API and digital audio inter­face reduce integ­ra­tion com­plex­ity and help shorten time to market.

50% reduc­tion in wiring
 com­plex­ity

Single-module 
integ­ra­tion

OEM-cer­ti­fied
 archi­tec­ture

Reduced
time-to-market

Conventional vs. Remote Tuner Architecture

System Level Comparison

 Con­ven­tion­al Archi­tec­tureRTM Archi­tec­tureBusi­ness Impact of RTM
Tuner Loc­a­tionInteg­rated in head unitTrunk lid / C‑pillar / Roof
(near anten­nas)		Optim­ized RF per­form­ance and improved signal quality
Antenna Amp­li­fi­ersMul­tiple antenna amp­li­fi­ers requiredAntenna amp­li­fi­ers elim­in­atedFewer com­pon­ents, lower BOM cost
Coaxial CableCoaxial cable runs from each antenna to head unitSingle digital inter­face (A2B / Eth­er­net)Lower mater­i­al usage, cost reduc­tion, weight savings
Heat Man­age­mentCrit­ic­al chal­lenge in head unitElim­in­ated by extern­al place­mentLower thermal stress, increased reli­ab­il­ity
EMI Expos­ureHigh EMI risk in dense head unitReduced EMI due to remote place­mentCleaner RF envir­on­ment, more stable per­form­ance
Head Unit Vari­ants (Global)8–12 SKUs2–3 SKUs75–85% reduc­tion in head unit part numbers
Integ­ra­tion TimeMonths of devel­op­mentPlug-and-play, sim­pli­fied API, pre-val­id­ated moduleMinimal adapt­a­tion effort, faster time-to-market
RF Per­form­anceLimited by dis­tance from antennaOptim­ized through prox­im­ity to antennaStronger recep­tion, fewer cus­tom­er com­plaints

Built for Demanding Automotive Environments

Designed to perform reliably across complex vehicle architectures.

Power Supply

9.0 – 18.0 V DC
with reverse polar­ity pro­tec­tion

Operating Temperature

–40 °C to +85 °C

Reception Standards

AM / FM / DAB / HD Radio

Primary Interface

A2B (Eth­er­net option­al)

Antenna Connections

Dual FAKRA con­nect­ors
Option­al MQS 3‑pos + Single FAKRA

Seamless Linking

FM–FM, FM–DAB, DAB–DAB, FM–HD

Global Product Variants

Configured for Regional Standards and Global Vehicle Platforms

Europe

  • Part Number: 920–787-101
  • Recep­tion Stand­ards: AM, FM, DAB
  • Fea­tures: Phase-Diversity, DAB MRC, Seam­less Linking, Data Tuner (TMC, TPEG)

USA

  • Part Number: 920–787-131
  • Recep­tion Stand­ards: AM, FM, HD Radio
  • Fea­tures: Phase-Diversity, HD MRC, Data Tuner (SDARS support on request)

Global

  • Part Number: 920–787-161
  • Recep­tion Stand­ards: AM, FM
  • Fea­tures: Phase-Diversity, Data Tuner

Trusted by Global Automotive Leaders Engineered for Your Success

Automotive-Grade Quality

With deep auto­mot­ive RF expert­ise, Hirschmann Car Com­mu­nic­a­tion deliv­ers stand­ards-driven con­nectiv­ity solutions—designed, tested, and cer­ti­fied to meet the highest auto­mot­ive require­ments, trusted by global OEMs, and proven in thou­sands of vehicles on the road.

Proven Track Record

Hirschmann Car Com­mu­nic­a­tion manages the full devel­op­ment life­cycle from concept to pro­duc­tion val­id­a­tion with advanced RF testing, global homo­log­a­tion expert­ise (EU, North America, China), and ISO 9001-cer­ti­fied man­u­fac­tur­ing to ensure con­sist­ent quality at scale.

Technical Support

Ded­ic­ated engin­eer­ing team ready to support integ­ra­tion, cus­tom­iz­a­tion, and deploy­ment for your spe­cif­ic plat­form.

Scalable Integration Options

Standardized or customized designs to match OEM architecture and program requirements

Off-the-Shelf RTM

A ready-to-integ­rate Remote Tuner Module designed for fast deploy­ment in series pro­duc­tion pro­grams

✓ Imme­di­ate Avail­ab­il­ity
Deploy within weeks, not months

✓ Proven Con­fig­ur­a­tions
Tested designs for auto­mot­ive plat­forms

✓ Lower Devel­op­ment Cost
Minimal engin­eer­ing, faster ROI

✓ Stand­ard Support
Doc­u­ment­a­tion, API, and tech­nic­al assist­ance

Customized RTM Solution

A tailored Remote Tuner solu­tion optim­ized for your spe­cif­ic vehicle archi­tec­ture and program require­ments.

✓ Tailored Design
Built for your spe­cif­ic OEM require­ments

✓ Custom Inter­faces
A2B, Eth­er­net, or pro­pri­et­ary pro­to­cols

✓ Integ­ra­tion Support
Expert engin­eer­ing team guides imple­ment­a­tion

✓ Long-term Part­ner­ship
Ongoing support, firm­ware updates, evol­u­tion

✓ Custom Chipset
Expert engin­eer­ing team guides imple­ment­a­tion

✓ Radio Type Approvals
Cer­ti­fic­a­tion of addi­tion­al coun­tries upon request

Ready to Simplify Your Radio Architecture?

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