Broadband parametric amplification with impedance engineering: Beyond the gain-bandwidth product

  1. Tanay Roy,
  2. Suman Kundu,
  3. Madhavi Chand,
  4. Vadiraj A. M.,
  5. A. Ranadive,
  6. N. Nehra,
  7. Meghan P. Patankar,
  8. J. Aumentado,
  9. A. A. Clerk,
  10. and R. Vijay
We present an impedance engineered Josephson parametric amplifier capable of providing bandwidth beyond the traditional gain-bandwidth product. We achieve this by introducing a positive
linear slope in the imaginary component of the input impedance seen by the Josephson oscillator using a λ/2 transformer. Our theoretical model predicts an extremely flat gain profile with a bandwidth enhancement proportional to the square root of amplitude gain. We experimentally demonstrate a nearly flat 20 dB gain over a 640 MHz band, along with a mean 1-dB compression point of -110 dBm and near quantum-limited noise. The results are in good agreement with our theoretical model.