Please enter all required values.
Formulas & Mathematical Logic
Step 1: Convert operating frequency to Hz, DC beam voltage to V, DC beam current to mA and repeller spacing to m.
Step 2: Output Power = (0.398 × Vo × Io × 10^-3) / N.
Step 3: Repeller Voltage = (6.451324898 × 10^-6 × F × L × sqrt(Vo)) / N.
Step 4: Electronic Efficiency = (0.398 / N) × 100.
Step-by-Step Example
Example: frequency = 10 GHz, beam voltage = 300 V, beam current = 25 mA, mode = 2, spacing = 0.02 m.
Step 1: Convert frequency to Hz using the selected unit.
Step 2: Convert beam voltage and beam current using their selected unit multipliers.
Step 3: Output power is calculated from beam voltage, beam current and mode number.
Step 4: Repeller voltage is calculated from frequency, spacing, beam voltage and mode number.
Step 5: Electronic efficiency is calculated as 0.398 divided by mode number, then multiplied by 100.
About This Calculator
Estimate reflex klystron power, repeller voltage and electronic efficiency.
The CalcBoy Reflex Klystron Calculator calculates output power, repeller voltage and electronic efficiency from operating frequency, beam voltage, beam current, mode number and repeller spacing.
A reflex klystron is a microwave oscillator tube that uses velocity modulation and electron bunching. Electrons are accelerated through a resonant cavity, travel toward a negatively biased repeller electrode, reverse direction, and return through the cavity. If the transit time is correct, the returning electrons deliver energy to the RF field and sustain oscillation.
This calculator is useful for microwave tube theory, lab reference work, educational RF engineering, oscillator analysis and comparing how mode number changes output power and efficiency. It preserves the supplied calculation logic for output power, repeller voltage and electronic efficiency while adding clear CalcBoy sections for practical use.
Real reflex klystron operation depends on cavity tuning, beam focusing, thermal condition, electrode geometry, repeller voltage stability, coupling, tube aging and high-voltage safety. Use the calculated values as theoretical estimates, not as a replacement for datasheet limits or lab measurement.
Best UseReflex klystron theory and microwave oscillator estimates.
Supported InputsFrequency, beam voltage, beam current, mode and repeller spacing.
Helpful ForOutput power, repeller voltage and efficiency study.
Design ReminderMicrowave tubes involve high voltage and RF hazards.
Safety note: Reflex klystron equipment can use dangerous high voltage. This calculator is for theory and educational calculation, not live circuit servicing.
Frequently Asked Questions
What is a reflex klystron?
A reflex klystron is a microwave oscillator tube where electrons pass through a resonant cavity, reflect from a repeller electrode and return to the cavity to sustain oscillation.
What does repeller voltage do?
Repeller voltage reflects the electron beam back toward the cavity and controls the transit time needed for RF oscillation.
What does mode of operation mean?
The mode number represents the electron transit timing condition used in the preserved output power and efficiency formulas.
What unit is output power shown in?
Output power is displayed in watts.
Can this be used for real microwave tube servicing?
No. It is a theory calculator. Real klystron equipment can contain hazardous high voltage and microwave energy.
Why does efficiency reduce when mode number increases?
In the preserved formula, electronic efficiency is inversely proportional to the mode number.