Multi-Channel Short-Range RF Circuit
Budget: $3,000 – $5,000 USD
I have working breadboard prototypes that use the common 315 MHz and 433 MHz ASK modules to trigger an identical downstream PCB. They prove the concept, but two frequencies are not enough: I need a transmitter-receiver pair that can be replicated many times and run side-by-side in the same room without crosstalk. The application is strictly consumer-electronics and will live indoors, so regulatory and environmental demands are modest, yet reliability and very low power consumption are critical.
Here is the operating envelope you will be designing for:
• Range: up to 3 m line-of-sight
• Transmitter supply: two AA cells
• Receiver supply: 9 V battery
• Duty cycle: momentary bursts, mostly standby
• Form factor: through-hole or compact SMD is fine; we will handle the final PCB layout in-house once the schematic is proven.
What I need from you
1. A complete RF circuit schematic that supports multiple non-interfering channels (more than two) in the licence-free spectrum—anything from custom-crystal-locked channels to digitally programmable solutions is acceptable as long as simultaneous operation in the same room is rock-solid.
2. Bill of materials with current, readily available parts.
3. Reference PCB layout guidance for trace-critical sections such as the matching network and antenna.
4. Bench test data or a simple demo setup that shows reliable operation on at least three distinct channels, each powering my existing load at 3 m.
Acceptance criteria
• Idle current on the transmitter must not exceed 5 µA; active burst <25 mA.
• Receiver must wake and react in <50 ms while averaging <8 mA.
• No observable interference when three or more sets operate simultaneously in a 5 × 5 m room.
We hold full CAD capability—Altium, KiCad, GERBER generation—so once your design is validated we can take it straight to production. If your approach naturally lends itself to features such as basic signal encryption or automatic channel selection, feel free to include them as options, but the core deliverable is the multi-channel, low-power RF link described above.
Here is the operating envelope you will be designing for:
• Range: up to 3 m line-of-sight
• Transmitter supply: two AA cells
• Receiver supply: 9 V battery
• Duty cycle: momentary bursts, mostly standby
• Form factor: through-hole or compact SMD is fine; we will handle the final PCB layout in-house once the schematic is proven.
What I need from you
1. A complete RF circuit schematic that supports multiple non-interfering channels (more than two) in the licence-free spectrum—anything from custom-crystal-locked channels to digitally programmable solutions is acceptable as long as simultaneous operation in the same room is rock-solid.
2. Bill of materials with current, readily available parts.
3. Reference PCB layout guidance for trace-critical sections such as the matching network and antenna.
4. Bench test data or a simple demo setup that shows reliable operation on at least three distinct channels, each powering my existing load at 3 m.
Acceptance criteria
• Idle current on the transmitter must not exceed 5 µA; active burst <25 mA.
• Receiver must wake and react in <50 ms while averaging <8 mA.
• No observable interference when three or more sets operate simultaneously in a 5 × 5 m room.
We hold full CAD capability—Altium, KiCad, GERBER generation—so once your design is validated we can take it straight to production. If your approach naturally lends itself to features such as basic signal encryption or automatic channel selection, feel free to include them as options, but the core deliverable is the multi-channel, low-power RF link described above.