So I am trying to implement the circuit described in this paper(https://ieeexplore.ieee.org/abstract/document/8846110) in LTSPICE. The circuit is shown below.

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https://preview.redd.it/4wutshj18n571.png?width=1222&format=png&auto=webp&s=5030718265454dba451b1914c383e59714ace093

This is the oscillator output:

https://preview.redd.it/del3lhmd8n571.png?width=1920&format=png&auto=webp&s=f447810b86283c5c2dd165be73ad8dbf6192ec21

The paper claims that the circuit can be used to measure the resonant frequency of the coupled LC tank. By changing the voltage of the varactor diode, the frequency of oscillation of the colpitt's oscillator is changed to generate a frequency sweep. At the resonant frequency, the emitter current(or voltage Ve) is maximum. However, on simulating the circuit, I get same value of Ve. The waveform of Ve is as shown below:

https://preview.redd.it/f8sfy3w38n571.png?width=747&format=png&auto=webp&s=65880ac055b18e54799fe565556875c525d2d99a

The expected wave form should be like a half sin with a peak. However I am getting the response as seen above. It doesnot change with the varactor diode capacitance, even though I have designed the circuit such that resonance should have occured when the varactor diode voltage will be 5V. Please help me out with this! I have no mentors to help me with doubts and stuff so I would really appreciate if someone here can take the time to help me out!