- reference body
- reference cavity
- reference frequency
- reference loss
- reference mode
- reference molecule
- reference noise
- reference point
- reference sensitivity
- reference signal
- reference surface
- reference symbol
- reflected beam
- reflected impedance
- reflecting satellite
- reflecting surface
- reflective gain
- reflector dipole
- reflector panel
- refolder
- reformat
- refractive effects
- refractive modulus
- reframing
- refresh mode
- refresh signal
- refurbishment
- regelation
- regeneration
- regenerative amplification
- regenerative circuit
- regenerative feedback
- regenerative repeater
- regenerator
- regenerator section
- regional agreement
- register allocation
- register block
- register compatible
- register set
- register translator
- recycle
- red adder
- red tube
- reduced data
- redundancy
- redundancy ratio
- redundant coding
- redundant level
- redundant routing
- reference atmosphere
- reference clock
- reference oscillator
- reference pattern
- reference receiver
- reference sensibility
- reflecting medium
- reflecting point
- reflection factor
- refractivity
- refractor
- refreshed image
- regenerated data
- regenerative amplifier
- regression
- regression line
- regular programme
- regulating pilot
- relation schema
- relative redundancy
- release system
- reliability factor
- reliability test
- rejection band
- rejection number
- relation cycle
- relative load
- relativistic effect
- relay set
- release
- reliability theory
- reliable link
- relocation factor
- remedial feedback
- reminder call
- remittance
- remote amplifier
- remote computer
- remote control
- remote detection
- remote device
- remote management
- reference chain
- reference frame
- reference picture
- reference station
- reference tape
- reference time
- reflected signal
- reflector antenna