Generating spike using decaying exponential sinusoid of frequency 10^7Hz

How to generate this spike?(Spike only. Not the sine wave). It should be generated with an exponential decaying sinusoid. The frequency of sinusoid is 10^7 Hz. If not possible to generate using exp. function, please suggenst other idea.

Answer 1

[Mathieu NOE]

hello

try this code ; I guessed the pattern period about 0.01 second but you can of course modify it

Fs = 1e7;
dt = 1/Fs;

one_signal_period = 0.01;
t=(0:dt:one_signal_period-dt); % remove one sample at the end ( dt) to avoid duplicate with next segment first point
a= 5*exp(-t/0.0007);
a(1) = 0;
b=1*exp(-t/0.0007);
b=flip(b);

y = a+b;
figure(1)
plot(t,y,'b');

% create repetitions of the signal
rep = 5; % repetitions
y_rep = [];

for k = 1:rep
    y_rep = [y_rep y*(-1)^k];
end

t_rep = (0:numel(y_rep)-1)*dt;

figure(2)
plot(t_rep,y_rep,'b');

[Reji G]

Accepted with heartful Thanks.......

[Mathieu NOE]

as always, my pleasure !